Sinclair User Magazine Issue 005

August 1982

The independent magazine for the independent user

Issue
No 5

ZX-81 ki

Giving your
Sinclair
a break

JJJ

i\

w

Programming
f without

tears

Rainy day
software
reviewed

Disaster in
Manchester

We profile
an award -winning
er

Spectrums
begin to roll

Meet
our first
Sinclair User
Club member

Eight pages of prcinms, your letters, helpline, mind games

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contents

Editor

Nigel Clark

Consultant editor
Mike Johnston

Production editor

Hamlrt Mayes MBE

Design

William Scolding

Editorial director
|ohn flterlicchi

Advertisement director
Simon Horgan

Advertisement manager
John Ross

Ed itorial''prod action assistant

Margaret Hawkins

Managing director
Terry Carfw right

Chairman
Richard Hease

Sinclair User is published monthly
by I '(.( Publications Ltd It i* mil in
any way connected with Sinclair
Research Lld-

Telephone

All departments
01-359 74BI

IT you would like In contribute to
Sinclair User. please send typed (or
beautifully hand-written) articles nr

programs to:
Sinclair User
ECC Publications,
30-31 Islington Green.
London Nl BBJ

We will pay E 10 for each program

printed and E50 for each article.

which should be appro simntBlv
1.000 words long.

■ Copyright 1982
Sinclair User
ISSN' No. 0262-545B

Original ion by

Outline Graphics.

Printed by

Eden Fisher (Southend) Ltd

Distributed by

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5 SINCLA1RVOY ANCE We look at how micros can boost the enjoyment of holidays in

the future.

6 HOLIDAY PROBLEMS Do ZX-81s become lonely when left behind at holiday lime?
Nicole Segre considers the difficulties lighl-heartediy.

9 MATHS GAMES Ian Stewart looks at ways of relaxing with numbers.

1 3 COMPUTES CAMP We profile Beaumont Computer Camps, where children can

learn about now technology in the Lake District.

14 SOFTWARE SCENE We concentrate on ways of using your ZX-Bl to occupy the
hours of poor summer weather,

19 NEWS The Spectrum begins to roll; a disastrous Microfafr in Manchester: ZX-Bl
sales boosl in the U.S.; and much more,

21 YOUR LETTERS Ynu tell us what you think about the world of Sinclair computers.

24 COMPACTER ROUTINES George Todorovic considers the problems of data code
compression on the ZX-Bl by changing the character codes,

27 STARTING FROM SCRATCH Our regular feature on how to begin using vour
ZX-S1,

29 TOO [-KIT ROUTINES In his second article, Phil Garrett looks at more aids for

prog ramming,

3 1 PROGRAM PRINTOUT Another eight pages of great programs from our readers.

39 ZX-99 Stephen Adams reviews this major piece of hardware from Dala-Assetlo.

43 HARDWARE WORLD Our regular look at what is new in the peripherals market,

45 MIND GAMES Philip Joy and mure of the games which test your mind.

47 HELPLINE Andrew Hew son answers your problems this month about the display
file do the ZX-Bl,

50 MOVIES Jack Knight describes easy ways in which to include moving graphics into
vour programs.

55 INSIDE SINCLAIR Claudia Cooke interviews Rick Dickinson, the award-winning

designer of the ZX-Bl and the Spectrum.

59 COMPETITION h ri: LhI is the theme for this month's contest for the last ai our
printers. i

61 SINCLAIR USER CLUB We speak to the first club member and there are three
special offers for members of nur ever-growing user cluh.

63 SPECIAL OFFER ZX-Bl kits for £29.95 plus postage and packaging — A saving of
£20.

66 ADVERTISEMENT INDEX Your guide to the many items advertised in the pages of
Sinclair User.

NEXT MONTH

• Special Education Edition — We look at
the uses for Sinclair machines and the
growing amount of software available.

SINCLAIR USER August 1B82

MELBOURNE HOUSE * ZX81 * SPECTRUM

You'd be smiling too if you were Dr. Ian Logan.

Dr. Logan is shown receiving the Rosetta Stone Award for
his perceptive insights into the way the ZX8I ROM
operates. Melbourne House are proud to be the publishers
of Dr. Logan's books.

Melbourne House are Sinclair specialists, publishing books
that are winners in every category. Whether you are a
beginner or an experienced programmer, you'll need
Melbourne House books.

If youVe got a Spectrum on order (or better yet. if you've
already got your Spectrum), then you'll be glad to know
that Dr. Logan is working on Understanding Your
Spectrum, sure to become the definitive book on the
Spectrum.

So if you want to smile like Dr. Logan, you can do one of
two things: Order one of our books from your bookseller
or fill in the coupon and really understand your Sinclair, or
you can write a great book or program and send it to us.
Who knows? Your smile may be in this ad, next year!

O Machine Language Mad* Simple For Your Sinclair, L8 9S

O Understanding Your ZXBI ROM. by Dr Ian Logan, i"&95

ZX8I ROM Disassembly Part A. by Dr 1m Login, 17 00

D ZXSI ROM Disassembly Part B by Dr Ian Logan and Dr Frank O Hara. 18 00

O Ndi only 30 Programs for the ZX8I: IX. \\6.n

O The Complete Sinclair ZXBI Bask Course, LI 7.50

JS*

Jf£ v

TOM*

— Order* to

__^__^; Melbourne House Publishers, Correipondence to Glebe Cottage,

1M, M.^H I 111 Trafalgar Road. Station Road, Chedtfin gion ,

™ ■■*■■ S G reerMch Leigh ton Buizard.

^*KP^ London SE 10 BEDS LU7 7NA

Please rush me- your new Spectrum.' ZX8 1 catalogue. (Please specify.)

Please send me books, as marked above Not*: Please add 80p for post, pack & VAT

Name

Address... . Postcode

MELBOURNE HOUSE • ZX81 • SPECTRUM

sinclairvoyance

Portable systems can
boost outdoor thrills

IT IS a bleak winter's day in ihe hiatus between Christ-
mas and New Year a few years in the future. The
thoughts of the family Typical-Sinclair-User stray from
the usual feast of old films and Christmas spectaculars
on television to visions of sue, sea and sand.

They switch off the television, attach their latest
Sinclair machine, bought from one of the many high-
Street stockists, add their Martochoice Prestel adapter
and turn to the Prastel holiday pages-
Following the eventual development of the adapter for
the Sinclair machines, Prestel enjoyed a boost in the
number of domestic users, A full range of holiday
operators have since found it worthwhile to give details
of their holidays all over the world.

The Typical-Sinclair-Users select a group of holidays
in which they are interested and request more details.
Those arrive on the screen immediately and are printed-
ouL Pictures of the resorts and the facilities arrive
through the post a few days later.

From those, the TSUs decide. Unfortunately when
they try to book, again through Prestel, they find their
first choice of time, destination and operator is fully-
booked. They bring their second choice to the screen and
find there are vacancies. They make their booking,
paying the deposit by debiting their bank account

"V"

directly by Prestel. Once that is done, a bill for tha
balance and a listing of the holiday details arrives on the
printer.

As the time for the holiday approaches theTSU family,
between playing the latest game of aliens and keeping
their household accounts in order, check the weather
conditions at their chosen resort and the strength of the
peseta against the pound — all available through
Prestel.

As the TSUs hate shopping, having to push their way
through the crowds, they decide to buy all their holiday
clothes and equipment by mail order, again using
Prestel.

Their tickets finally arrive, printed on the ingenious
micro colour printer developed by Sinclair Research.
That add-on had been produced in response to a number
of attempts by other companies to make something
which allowed a record to be kept of the Spectrum
displays and the claim by a number of people that not
even Clive could produce a colour printer al a
reasonable price.

Pausing only to cancel the milk and Sinclair User — by
Prestel, of course — switch off the Sinclair-controlled
air-conditioning system and transfer cunt rol of the home
security to the neighbours* Sinclair so that they can look
after the house, the Typical-Sine lair- Users begin their
great adventure.

The luggage consists of the usual suitcases but also
includes a large black briefcase. When they arrive at the
airport, they find many other families have the same
black briefcases, All are treated with great care, are
taken inside the aircraft as hand luggage and stored
carefully under the seals.

They arrive in Majorca, everyone still taking great
care of their black cases. On reaching their hotel
everyone immediately rushes to their rooms, where the
secret of the black box is revealed. Inside there is a
complete Sinclair computer system, neatly packed in
plastic foam. The VDU is one of the Sinclair flat-screen
televisions and it is powered by a lighl by I powerful
battery developed as part of Iho Sinclair electric car
project.

The following day the TSU family goes to the beach
ond. in common with niiinv itinera. the\ take their
briefcase and spend half the day enjoying the sun, sea
and sand and the other half playing with thu Sinclair,

The case also contains a device which allows the
Typical-Sinclair-Users to contact their neighbours via
the telephone service or collect any recorded messages
on their telephone answering service.

If this sounds a little far-fetched, as though the
Sinclairvoyance crystal ball is even less clnur than
usual, consider that most of the items are already in
existence and are available either for the Sinclair
machines or can be adapted from hardware available
with other computers. The two items which do not exist
are the colour printer and the lightweight battery but that
is no guarantee that they will not appear on the market.

The rest of this look into the not-toondistant future
depends on how people react to the possibilities
provided by a light, fully-portable computer system. It
may be a little unreal to suggest lhat people will take
every opportunity to avoid leaving their homns. [1 would
be pleasant to think that the gregarious nature of people
would rebel against being cut off from iheir fellow
human beings.

The enthusiasm with which many lake any
opportunity to cut themselves off and carry around their
own little world, however, would appear to argue
against this. II is one of the reasons why cars are
preferred to public transport and why growing numbers
of people can he seen walking around with haedphonns
listening to small cassette players.

SINCLAtRUSER Augustl'MI?

ENJOYABLE though it may be
for some, holiday time has
always brought its special
problems. I do not mean only
dilemmas such as what one wears
— if anything — in St Tropez, or for
hang-gliding over the Niagara Falls,
or for whatever other delights one
has in store. I speak of real anxieties
such as who will water the
plants.Even if the cat could be
persuaded to do it, who will feed the
cat? How will the burglars be lured
into thinking that three burly men
are in residence when the whole
street looks more dead than John
Geese's Norwegian blue parrot?

Now, to add to all that, there is a
new problem — what happens to my
son's ZX-817 I realise how silly it
sounds but I have to confess that I
have wondered whether it would be
all right on its own. Would it rust?
Or do chips go stale for lack of use?
Would dust get into its nooks and
crannies and make it behave
strangely, like something taken-over
by beings from outer space? Would
Alex on his return from holiday be

Do Sinclair machines get lonely being
left at home during summer holidays?
Nicole Segre considers the problem,

Taking the pain out
of holiday separation

have those names correct. Will that
American university, which gave us
Rubik's thumb and Clacker wrist,
discover another ailment associ-
ated with popular pastimes? ZX
addiction perhaps, or more likely
Sinclair Eye. I can imagine
thousands of people wandering
around wearing dark glasses on
even the dullest day as they walk for
the first time in the open air for some
months, their hands twitching as
they suffer withdrawal symptoms
from using the keyboard,

I need not have worried, though,
and 1 feel much better about it after
a brief talk I had with Keith HalL I
should explain that he is res-
ponsible for all the computer
madness, or Sinclair Syndrome, in
our household. He introduced my

*No longer need Sinclair users endure
long weeks of computer deprivation; they
can take their computers with them. 1

wandering about saying: "I know
you think I'm crazy but that is not my
computer. It looks like my computer
but something has happened to it. It
is not my computer",

Have I been watching too many
late-night films? Do computers have
feelings? Should I ask someone to
come each day not only to feed the
cat and water the plants but to dust
the computer and talk to all of
them, too? Lest but not least, how
would my son cope with the strain of
a whole summer unrelieved by a
single game of Monster Centipedes
or Asteroids' Revenge — I do hope I

son to the ZX-B1 by starting a com-
puter club at his school. I hasten to
add that in every other respect he is
a splendid chap.

He told me that one reason the
Sinclair is so eminently suitable for
school use is that its keyboard,
which many of us agree is
maddening to use, is also very
resistant, able to withstand spilt
drinks and countless sticky fingers,
never mind a little bit of duBt. In fact,
one ZX-fll has even been run from a
car battery in a muddy back garden,
without ill-effect.

Further, it appears thai my oft-

repeated complaints about the
Sinclair never doing anything useful
are completely unfounded. Accord-
ing to Hail, with the necessary modi-
fications and appendages — I will
not go into all the technical details
as I do not want to confuse you — the
Sinclair can be made to do almost
anything. Even feeding the cat and
watering the plants, I dare say,
although I would not trust it to know
which was which and certainly not
to speak to them pleasantly.

This opens-up an interesting pos-
sibilitv. No longer need Sinclair
users endure long weeks of com-
puter deprivation; they can take
their little computers with them.
While those of us with more old-
fashioned tastes splash about in the
waves or walk through breath-
taking scenery, they could be sitting
within wire's reach of a car engine,
eagle eyes trained on a screenful of
moving blobs, astounding the locals
by their skill and by the amazing
advances of British technology.

It could be the start of a com-
pletely new way of spending
holidays. Beach computer clubs
could spring up in the resorts of
Europe — or more likely car park
computer clubs. Parents could be
seen rushing into the sea to rescue
machines caught by an unexpected
wave. Sand-castle competitions
would be a thing of the past,
replaced by attempts to make the
highest score on the car race game.

Perhaps they could even find in-
genious new tasks for their com-
puters to perform — testing the
temperature of the water, perhaps,
or acting as mosquito early-warning
systems. It would be a simple matter

S fNCL A IR US EH A ugust 1 982

holiday
problems

to store a few useful foreign words
end phrases such as "Where is the
nearest football stadium?" or "1
would like to speak to the head
waiter".

On second thoughts, it all seems a
little impracticable. If you took your
computer on shopping trips to
display requests like "Please give
me the yellow one", you would not
be able to carry your shopping.

A trip to the beach would go like
this: "Do you have your swimsuits?
Towels? Beach mat? Parasol? Ball?
Frisby? Sunglasses? Camera?
Binoculars? Radio? Computer?
Television set?" Somehow, I do not
see it. Besides which, even if there is
room to pack a computer on the out-
ward journey, there would not be on

the return, following that well-
known phenomenon by which suit-
cases always become smaller on
holiday, or the contents grow bigger
— it has not been proved con-
clusively either way.

Alternatively, 1 send Alex to one
of those computer camps, the
Butlins of the micro world, where he
can enjoy outdoor activities as well
as crouching over his computer. I
suppose that is intended to make
him physically fit enough to be able
to spend the rest of the year wth his
Sinclair without too many ill-effects.

The more I think about it, though,
the more I think this is getting out of
hand. Our lives are not to be ruled by
a small plastic box, no matter how
full it is of electronic marvels. The

last few months have been bad
enough, without it deciding how we
should enjoy the brief days of good
summer weather.

I am going to put my foot down
firmly and oppose any moves to take
a Sinclair away with us this year. A
break with the trappings of civilis-
ation will do us all a world of good.
Enough of flickering screens,
moving targets and exploding
galaxies — we shall restore our-
selves with fresh air, sunshine and
bird-song.

Now if you will excuse me, 1 must
go and pack. If 1 hurry, 1 might even
have time for a quick game of
Colliding Space Intruders, es it will
be a long time before I have the
chance again.

SINCLAIR USER August iS82

Use your computer in the case...

Foam rubber gives complete protection...

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Turn your ZX system _
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You r ZX ll ard w a re - ZX8 1 or S pectru m -
is designed to work together as a system.

And now there's a simple way to make
the most of the fact.

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A ZX Custom Case holds all your
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now available!

piece of equipment is gripped securely by
shock-absorbing foam. Each connecting
lead Tits under the foam, so there's no
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firmly, connections arc excellent.

You can forget Wasted lime setting up or
unhooking the system, too. When you've
finished, simply tuck in the mains and TV
leads and replace the hinged. Liti-offlid.
And of course, if you're taking your ZX
system lo college or the alike, ZX Custom
Cases are a lot less cumbersome than a bag
or rucksack. And a lot more protective and
professional

Designed by ZX enthusiasts -
for ZX enthusiasts.

Both the ZX81 and Spectrum Custom
< uses were designed by a group ofZX
system users and manufactured by Britain's
leading ease makers. Made from impact-
resistant ABS,each case holds every piece of
Sinclair hardware available for the
respective computers -plus Learning Lab,
manual, software cassettes and any cassette
ayer up to 10 ' 2" x 5' ■*". If you haven't all
ic hardware, simply leave the p re-cut
bam in position, then remove it as you get
extra pieces of equipment.

A nd when brand tteto hardware is
ititraduiid, or you upgradrJTimi ZX8t to
Spectrum, simplv contact usfor a replacement
foam insertforjmt £4. 95 (+pihp).

Send for your ZX Custom Case -now:
ZX8] and Spectrum Custom Cases arc
guaranteed for two years, and cost iust
£34,9 i > ( I- p&p) each. Remember you could
pay more for an ordinary briefcase,

To order, simply use the FREE POST
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telephone 0276 62l^,Mon-Fri,9.i0-5.1Q.

COMPUTEX

( inrnpulex Cases (JHSk Slanhopt Road,
t iimherkv. Sumy, GUIS UPS.

i'lnsiT jlh'.u ih Jj\-s itir Jflivcrv I L dw) m-aiw h^'kunderiikinn

laiComptLi** Cut* ( J B St, FREFPOST,
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il'LCUllI Mi<

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Siuruiun:

Njiiic At i Mrf/MtM

Address

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I Kctm f'.FvpJjnd no '.•■•

sirs Jew*

maths
games

MATHEMATICIANS call it
iteration — repeating a
process over and over
again to sea what you get. Which
means, fancy names notwithstand-
ing, that it should be easy meat for a
computer. Because, after all doing
the same thing over and over again
is what computers do best.

I do not mean exactly the same
thing, of course — not like the
student who was asked. "What do
you get if you add 3 to 4D three
times?" and who replied "I get 43
every time". I meen the same pro-
cess but using the result of one stage
as the starting-point for the next.

For instance, suppose the process
is "add the digits". If we start with
479. then adding the digits gives
44.7 + 9 = 20. Now iterate, by
adding the digits of that: 2 + = 2.
Iterate again, well; it is 2 + nothing
else, that is 2 again. So we are stuck
at 2. It is reasonably easy to see that
whatever number with which you
start you will eventually get down to
a one-digit number, and stop. So that
is not worth taxing the poor old
ZX-81 brain.

What if we add the squares of the
digits? Then 479 would lead to
4*4 + 7*7 + 9*9, or 16 + 49 + 61,
which is 136 — well, 146, I made a
mistake; and that — well, perhaps
the ZX-B1 is good for something
after all. Let us write a small
program to do the iteration for us:
10 INPUT N
20PRINTAT19.0;N
30 LET A =
40 LET M = INT(N/10)
50 LET A = A + (N-10*M)*

(N-10*M)
60 LET N = M
70IFM = THEN GOTO 90
80 GOTO 40
90 PRINT AT 20,0;A
100 SCROLL
110 LET N = A
120 GOTO 30
See what it does? You give it the

SINCLAIR USER August 1982

Relax with a pretty
number pattern

Ian Stewart looks at a rewarding way
in which to spend a few hours playing
with number series and loops

starting number N. It uses A to add
the squares of the digits — those
(N-lO*M)s are the digits — and
prints it out; SCROLLS to make room
for the next step; then sets N equal
to the result A and goes back to line
30 to start all over again, iterating
like mad,

Type it in; tryafewvaluesforN.lt
will go on forever unless you hit

BREAK, but keep watching —
perhaps you will notice a pattern.

What happens eventually is that
the numbers settle down to some
kind of regular behaviour but it can
be a surprising one. For instance,
try N = B9. You will get, success-
ively, 145, 42. 20, 4, 16, 37, 58, 89.
The iterations brought us back to
continued on page 10

tgtt

A

A

continued 1 from page 9
where we started and the silly beast
is going round in an endless loop.
You will find that many starting
values for N lead into the same loop.
That is interesting, really, you
would not have guessed it initially.
Some numbers do not get into that
loop, though; try N = 7 as a starting
point. You can have plenty of fun
trying different starting values and
comparing the way the numbers
evolve.

If squares are not for you,
perhaps you would prefer cubes?
Thanks to Professor Rubik they are
fashionable but our cubes are things
like 2*2*2 = 6. or 3*3*3 = 27. Just
modify line 50 of the program to read

50 LET A = A + (N-10*M)*
(N-1D*M)*(N-10*M)
and proceed as before. This time
there is a new surprise — the
number 153 goes to itself. There are
some other numbers which equal
the sum of the cubes of their digits:
can you find them? On the other
hand there are some loops, too; for
instance

133— 55~* 250— 133 — . . .
Insert yet another (N-10*M)* in
line 50 and you have fourth powers.
Here is a nice loop, too:

4514- 1138 -* 4179- 9219-

13139— 6725— 4338 — 4514-

Fifth powers? You should be able
to work out the modification to the
program by now. There is a loop of
length four:

10933 - 59536 - 73318 —
5QQ62- 10933- . . .

Experiment with different
powers and different starting-
points N. It is a relaxing way to
spend a few hours and there are
plenty of patterns to spot. The one
general thing which is known is that
from whatever number you start,
you must eventually end in a loop, or
with a number which goes to itself,
forming a loop with only one number
in it.

Essentially that is because if you
start with a big enough number the
sum of the powers of its digits has to
be smaller; so the numbers keep
shrinking until they are trapped in a
limited range. Once there, they hop

around and since they cannot keep
going to different values forever,
there being only a Limited range
available, something has to repeat.
There is one amazingly simple
iteration process about which
nothing of the kind has ever been
proved, even though most people
think it must be true. It is called the
JCakutum Problem. The iteration
process is:

If N is even, halve it.
If N is odd, treble it and add 1.
Problem: does everything end in
the loop 1-4-2-1-,..?
Here is the program:
10 INPUT N
20 LET C =
30 PRINT AT 20,0; N
40 SCROLL
50IFN = 2*lNT(N/2] THEN

LET NO + N/2
60!FNO2*INT(N/2)

THEN LET NO = 3*N + 1
70 LET N = NO
80 LET C = C + 1
90 IF N = 1 THEN GOTO 110
100 GOTO 30

1 10 PRINT AT 2 1 .0; ' 'HIT LOOP

IND";C;"D STEPS'"

(□ = SPACE]

If you experiment with this, you

will find that the behaviour is most

irreguier. For example, N = 29 hits

the loop after 19 stages and so does

N = 30; but N = 31 requires 106
steps to reach the loop and the
numbers become as big as 1760 on
the way. Then 32 stops in only five
steps and 33 in 26 steps. The num-
bers hop around all over the place;
they get smaller, smaller —
suddenly bigger instead. Could they
keep growing forever and miss the
loop completely? Nobody knows,

Of course, you cannot decide that
on a computer; there is no way to
carry-out the computation forever,
to see if it keeps growing. You can,
however, have a general feeling
about the way the numbers behave
by trying them. A biggish start, like
1111111, hits the loop after 185
steps. Generally, runs where the
numbers shrink tend to occur more
often than ones where they grow.

Despite that evidence end an
enormous number of computer
experiments, the problem remains
completely unsolved, which is
remarkable, considering its sim-
plicity. It shows that there is plenty
of life left in mathematics and that
not every problem can be solved just
by putting it on the computer. It is
also an intriguing example of
elusive number patterns and the
computer is a valuable aid in finding
them.

10

SINCLAIHUSER Augustl982

«

//

".the quality of the colour display is excellent" Popular computing weekly.
The graphics facilities are great fun" Personal computer wxtf .
the Spectrum is way ahead of its competitors" Your computer.

"The world's best
personal computer

for under £500"

Sinclair ZX Spectrum

16KRAM £125, 48KRAM £175.

This is the astonishing new ZX Spect rum
- a powerful professional's computer in
everything but price!

There are two versions - 16K or a
really powerful 48KL Both have a full
8 colours, sound generation, a full-size
moving-key keyboard and high-resolution
graphics. Plus established Sinclair
features such as one-touch' keyword
entry, syntax check and report codes !

Key features of the Sinclair
ZX Spectrum

Full colou r - 8 colours plus flashing
and brightness-intensity control.

Sound - BEEP command with
variable pitch and duration.

Massive RAM -16K or 48K.

Full-size moving-key keyboard -all
keys at normal typewriter pitch, with
repeat facility on each key

High resolution- 256 dotshorizontally
x 192 vertically, each individually
addressable for true high-resolution
graphics

ASCII character set - with upper- and
lower-case characters.

High speed LOAD & SAVE - 16K in 100
seconds via cassette, with VERIFY and
MERGE for programs and separate
data files

The ZX Printer - available now

The printer offers ZX Spectrum
owners the full ASCII character set -
including lo we rcase characters and
high-resolution graphics.

Printing speed is 50 characters per
second, with 32 characters per line and
9 lines per vertical inch

ZX Microdrive - coming soon

Each Microdrive will hold up to 100K
bytes on a single interchangeable
microfloppy - with a transfer rate of
16K bytes per second And you'll be
able to connect up to 8 ZX Microdrives
to your ZX Spectrum - they're available
later this year, for around £50

How to order your ZX Spectrum

BY PHONE - Access. Barclaycard or
Trustcard holders can call 01-2000200
for personal attention 24 hours a day,
everyday.

BY FREEPOST - use the coupon
below. You can pay by cheque, postal
order. Access. Barclaycard or Trustcard

EITHER WAY - piease allow up to 28
days for delivery, And there's a 14-day
money-back option, of course We want
you to be satisfied beyond doubt - and
we have no doubt that you wifl be.

I To Sirreianr Research FREEPOST, Camburlpy. SufrGv. GUIS 3BH
I

Qty Item

Code Hem pries Total

■■■■■■■ " ■■■■■■ BBBBBBl I flBim " OBBBBH

ZX Spectrum

Sinclair Research Ltd,

Stanhope Road, Camberley, Surrey,
GU15 3 PS Tel: Camberley (0276) 685311.

Sinclair ZX Spectrum -
l6KHAMviM:,itci

1Q0

125 00

Sinclair ZX Spectrum -

48K RAM verir, i

101

175 00

Sinclair it -mi"!."

It

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Pnnier paper

l.rjack 01 5 rolls)

16

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Pottage arm pactortg
or ders under £ 1 00
orders over £100

SB

29

2 95

4 95

aselic* ii yyu mqulrsi VW ".-<.•

■i encloses cheque rpesia-i ofJe' pwttie to Sinclair
Rasa-arch Lid lor £

* Pi#as-e -charge lo my Access/Bai clayeafcJ/TfustcafcJ

account no. Please pnnl

•Please dtrletB/complBlH as applicable

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FREEPOST- no stamp n«#d*d. Pitee* apply to UK only. Export priceson application.

l SUS BO a |

SLNCLA1R USER August I3A2

! l

7 voi ra

£-/\Ul\h

TCI

ii

from
J.K. GREYE SOFTWARE LTD

me i it at UttitKht tut i Dur i wntst. t iuUJC

"Without question the finest machine code games available

today!: J-N. ROWLAND Producl Managst (or W H SMJTH.

GAME 5T APE 1 For IK .

ortlOM

ASTEROIDS UFO. COM. BOMBER
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We ve <*nna in 11,
require Ifjk l<? no 1

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■STARFIGHTEFt ftuperu machine code Space BaTflc Sut
agains-r a background of twinh,lir>Q *tan). Willi stunning

puflln^Mjna if yUu irfir* hit the enemy'

PYRAMID r,tn y*u mo*e ih-a F*vr"am^a? Make a rnistakB and
iimllcodlapM 1 A Thinker&ojamt

ARTttT The ultimate Graphic OAxigrvi aid. 6 Directions., 10
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'ID DEFENDCR The Uinmatr Space Gains

Machine Code 3D verson nt the Arcade tavouhte. You have

to save your hom? Manet horn the marauding Alien Spacecraft

Thia « all in 30, -you* viewscieen shows y«u the view out

ot your fiorireri cockpit window f h* batkdro* rncves *hen

yrju turn or tly up or down (El flight dneclmnal. |iiat a* ir you

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and al this price you c*n'i go w'Oflfl I

GAMES MARKED * INCL- MACHINE CODE.
Prices include VAT and U.K. P. & P.
4 Add appropriate Postage oo Foreign Orders). Cherjuus/P.O.s to

J.K, GREYE SOFTWARE LTD

DeptJtf, 16 Park St., Bath, Avon BAI 2TE.

CREDIT CARD SALES. Phone 01-930 9232 19am 7 p.m.)
FOR INSTANT DESPATCH

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TRADE & EXPORT ENQUIRIES WELCOME

OCCAM BOOKSHELF

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by Ian Stewart & Robin Joiles

A gcnile in I reduction to the ZX8I & its capabtltriK.

NOT ONLY >ft PROCJRAMS/SINCLAIK /.\S I : I K £7,25

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tach program.

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The Z80 Mkroprocessor, it* machine code, and how lo use machine
code subroutines in BASIC programs.

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A complete disassembly of hex. Locations QOOfl to OF54 with a

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Discover the LntcrnHl mysteries of the Sinclair^ and learn to
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ALL PRICES INCLUSIVE OF VAT &
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t Kt liiii Software , 13 Hawthiim drove,
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England, P.S, S heard.
Telephone: Wiimslow 524228.

Great games packs for 16K ZX81
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12

SINCLAIR USER Autfu;,! IW2

computer
camp

Hundreds of teenagers will this
year be able to learn all about
the Spectrum and the ZX-81
against the picturesque backdrop of
the Lake District. Beaumont
Summer Camps has decided to
instal a number of the machines at
its new residential camp six miles
south of Carlisle,

Children between the ages of 10
and 17 are able to enjoy holidays at
the camp in which half the day is
spent working on the Sinclair
machines and the other half can be
used to take part in the many other
activities available.

According to the organisers, it is
assumed that most of the children
will have no previous experience of
computers of any kind. They say
they have ""designed a special pro-
gramme to ensure that the campers'
first encounter with a computer is
most enjoyable and rewarding ex-
perience."' They also promise to
"de-mystify the computer".

Three levels of instruction are
provided to take account of all levels
of knowledge, The subjects covered
will include how computers work,
computer jargon, programming in
Basic, possible future applications,
and progress to floppy discs,
graphics, word processing and
other languages.

It is expected that most of the
campers will have a working know-
ledge of Basic programming after
two weeks.

The computer course is linked to
the other activities available at the
camp, which mainly involve moving
outdoors and enjoying the magnifi-
cent countryside. The camp pro-
vides tuition in camping, fell walk-
ing, sailing, pony trekking, canoeing
and many other activities.

It was the idea of Stewart Wiley, a
former holiday tour operator who
decided to set up holiday camps for
children after he had seen the
success of similar camps in the
United States.

Computer camps were introduced to
Britain last year and proved so popular
that they have been expanded rapidly.

Picturesque setting
for micro courses

"When 1 was on holiday in the
Stales. I saw a television pro-
gramme about a computer camp
which had been started in Santa
Barbara. California. 1 contacted the
person who had sal it up and he

visited England to advise on the
setting-up of a similar camp in
Britain," Wiley said.

Last year he openedhis first camp
at St John's School, Windsor — a
day camp with buses taking
children from the area to the camp
every weekday.

As at the residential camp, the
activities included outdoor sports
and the opportunity to learn about
microcomputers. At Windsor the
programme was based on the

Commodore Pet. It was not until this
year and the decision to set up a
residential camp that he became
involved with Sinclair machines.
They are now the only machines
available at the Carlisle camp. At
the day centre the courses use Vies
and Tanriys.

Rubin Heath, director of the
computer camps, said that one of
the reasons for choosing Sinclair
machines was that the average age
of children at the residential camp
would be higher than that at the day
centres,

"Younger children can have
difficulty with the keyboards on
both the ZX-61 and the Spectrum
but the average age at the Lake
District camp should be about 13
and many children of that age
already have ZX-Bls and find no
problem with them,'" Heath said.

He added that sine:e the decision
they had found the machines to be
very resilient and that would be an
advantage in being able to with-
stand the extra use,

"I made the decision to choose
Sinclair exclusively because I
thought it would be worthwhile for
the future to have a close
association with thecompany," said

Wiley.

The first venture at Windsor was
so successful that Wiley decided on
a massive expansion for this year.
As well as the Windsor camp and
the new Lake District residential
camp, there are other day camps
being organised at Mill Hill on the
outskirts of London, at Sevenoaks,
Kent, and Knutsford, Cheshire.

"Last year was very successful."
said Wiley. "We had spaces for 300
and could have filled them many
times over".

StNCLACRUKER Auj>usM!H»2

13

Phil Garrett looks at ways
of enjoying your holiday
despite poor weather

Greye defender is
another 3D winner

IF YOU ARE the type who
goes to the seaside to
spend hours — and pounds
— in amusement arcades,
there is a new crop of
ZX-fll action games to
tempt you to stay at home.
J K Greye, famous for its
remarkable 3D Monster
Maze, has scored again
with 3D Uef entk-r . This a!l-
machine-code game for 16K
ZX-SIs has the player steer-
ing the last surviving craft of
a once noble battle fleet into
action against marauding in-
vaders. Using the keyboard
like a joystick, you can
climb, dive and bank, watch
the stars wheel about and the
ground slip past, but keepan
eye open for the bad guys

and their plasma bolts. The
game requires quick reac-
tions and good co-
ordination — a minimum of
five fingers are in action —
and takes a good deal of
practice before any score is
achieved, Amazing graphics
effects are created as the
enemy draws closer, more
and more detail appearing as
the flymg saucers loom in
your forward scanner.
Another winner for £3.95.

It you have spent the
money you had saved for
your RAM pack on your
holidays instead, J K Greye
offers arcade-game action in
just IK. Its full-screen
Breakout, written in an in-
credible 500 bytes of

machine code, has all the
capabilities of the bigger
versions. The bricks are
inverse £ signs, which turn
into $ signs wh«n hit, and
then disappear altogether
when hit again. The game
has adjustable bat size
and speed, plus on-screen
scoring and variable re-
bound angle. All for £1.95
from J K Greye Software,
16 Park Street, Bath.
Avon, BA1 2TE.

Taste of exotic
from Diggles

ONCE YOU have returned
from your two weeks in the
European sun, how can
you recapture that taste of
the exotic? Photographs
and souvenirs are all very
well but what about food?
Your 1 6K ZX-fll can revive
those memorable meals
with the aid of The Diggles
Kitchen, Volume one
contains 28 recipes from
all over the world —
Cyprus chicken, Spanish
hake, Italian roast lamb,
plus recipes for beef, hare,
turkey, duck, ham and
many more. If you have

had enough of foreign
food, you will find
Lancashire hotpot and
steak and kidney pie
included. If you did not go
overseas this year, why
not turn up the central
heating, serve Hawaiian
pork, and dream a little?

The Diggles Kitchens,
volume one end volume
two — European recipes-
cost £4.99 each or £9 the
two From Micro Computer
Software, Unit D6, Pear
Industrial Estate, Stock-
port Road, Lower Brad-
bury, Stockport SK6 2BR

Carnell
adventure

IF YOU are bored with
soaking-up the sun, or can-
not become enthusiastic
about a day t rip to Clacton,
how about widening your
horizons with an Adven-
ture? Carnell Software
has produced three 16K
cassettes, each with an
adventure and another
substantial game.

In Volcanic Dungeon,
you enter the realm of
myth and magic to rescue
the Princess Edora from
the three-fold clutches of
the goddess of evil, the
Snow Queen, and the
Witch of the Black Moun-
tains. You are given a map
of the 90 connected
caverns, filled with
monsters, pits and fire. Ar-
mies of goblins and ice
giants await. Weapons
and magical objects are
scattered around and you

must watch your strength
and water levels.

Also tin the cassette is
Hangman with a built-in
400- word vocabulary; the
program allows for easy or
difficult words, one or two
players, and has full
screen graphics.

In Alien Intruder you
wake from cryogenic
suspension to find that the
rest of the starship crew
has been eaten by an alien
monster — and it will soon
be dinner-time again, A
graphics display shows
any life forms on the same
level — the ship has three
levels — so you can watch
the alien move closer.

Another display shuwa
what exits are possible
from the room or corridor
you are in, and a third
display shows what you
have been able to load into
your space shuttle craft,
which is your only hope of
escape. Food, water, oxy-
gen, weapons and other

useful objects are scat-
tered around.

On the other side of
Alien Intruder is Hiero-
glyphics, a clever varia-
tion of Hangman, in which
a 39-symbol ancient

14

SINCLAtRUSER AususU982

software
scene

alphabet has to he
deciphered before the
famous explorer, Wullie
Makeit, is buried in sand.
Both programs make good
use of graphics and words
to make a very entertain-
ing package.

WumpuB Adventure
features the most ancient
and terrible creature of
computer mythology. You
must track the Wumpus by
its smell and chilling cry
through a maze of caves
containing a host of ter-

rors.

Goblins may catch you
and tie you up as a morsel
for their god, the Wumpus;
bats may pick you up and
drop you in another cave,
which may contain a bot-
tomless pit or a giant ser-
pent — or only a swamp if
you are lucky. Up to four
players can take part and
if you happen to step into
Wumpus muck, one of the
other players may smell
you and fire an arrow at
you, in mistake for the
monster.

With Wumpus Adven-

Hangman costs £4,50 and
the other two tapes are E5
each, plus 50 pence p&p,
from R Carnell, 4 Stainton
Road, Slough, Berkshire.

Asteroids
in the home

INSTEAD of waiting for
the amusement arcades to
open, the Electronic Pencil
Co Asteroids brings home
the action. It has nearly all
the features of the 20
pence guzzlers; one or two
players, four sizes of
asteroids, hunter-killer
alien spaceship and on-
screen scoring. There are
five levels of play and the
top five scorers have their
names displayed.

Written in 100 percent
machine code, Asteroids
costs £3.95 from the Elec-
tronic Pencil Co.

ture there is Movie Mogul ,

which gives a taste of the
trials and tribulations of
Hollywood. See a day's
filming go down the drain
when the leading actor
punches the leading lady
in the mouth; try to
balance location and
studio filming, while keep-
ing in mind the current
fashions among the movie
buffs. Wumpus and Mogul
are two good non-graphics
programs to keep you off
the beach for hours.
Volcanic Dungeon/

Machine
tools

MARTIN Wren-Hilton, the
U.K. correspondent of the
American Sync magazine,
has taken time from his A
level studies to produce
two remarkable machine
code programs for 16K
ZX-Bls. The first, Super-
Zap, sounds like yet
another space invaders
game but is in fact a
separate loading and sav-
ing routine, entirely dis-
tinct from the routines in
the Sinclair ROM.

Many machine code
programs now available
start running automati-
cally after loading and
since they often use their
own keyboard scanning
routines, they do not res-
pond to the Break key.
Wren-Hilton wanted to be
able to look at those

cfmtmu&i on pm^e IB

SINCLAIR USER Au^us! 1982

13

continued frvm puge 15
programs and see how
they worked, so he devel-
oped Super-Zap, which
loads the program byte hy
byte into a Basic array, so
that it can be examined
without running it. That
array can then be saved on
tape, either in its original
format so that it auto-runs
on loading, or in a super-
zapped format, in which
case it does not.

Wren-Hilton"s second
program is Lower Case,
which alfows mixed upper-
and lower-case letters to
be output Lo the printer.
The program re -sets
RAMTOP and stores its
IViK of machine code
above it. A simple USR call
operates the special Copy
routine, which turns any
inverse characters on the
screen into lower-case on
the printer. True
descenders occur as
required and the routine
runs as quickly as the
normal copy. The number
of lines to be copied can be
altered with a POKE and
the routine has a typing
program developed by a
satisfied user.

Super-Zap and Lower
Case cost £4.95 each from
Martin Wren-Hilton, 4
Little Poulton Lane,
Poulton-le-Fylde, Nr,
Blackpool, Lanes FY6 7ET.

Silversoft
arcade

THERE ARE two more pro-
grams from Silversoft in"
case you caught Ihe ar-
cade itch at the seaside.
Asteroids has thrift: sizt:s
of asteroids, left and right
turn, fire and thrust OQQ*
trals. There are 10 levels
of play from soppy to
suicidal, with bonuses for
knocking-out the mother-

ships. On-screen scoring
and high score make this a
good all-machine-code ver-
sion of the game for £5,95,
Space Invaders is the
closest yet to the arcade
original. It has 10 levels of
play, command ships,
plenty of bombs to dodge,
smooth machine code ac-
tion, on-screen scoring

and high score, Like the
original, when you reach
the last few invaders they
start moving faster, so a
steady hand and a good
eye are required. If you
manage one screen, the
next group start one step
further down.

As an extra bonus, the
program includes the soft-
ware necessary to run the
Quicksilva character
generator, for even more
realistic invaders action.
It costs £4.95 from Silver-
soft, 40 Empress Avenue,
llford, Essex.

Playing for
high stakes

IF YOU have decided on
Littlehampton rather than
Las Vegas for your holiday
this year, you can still
taste the high stakes
action with two 16K
programs from Newline
Software. Three Card

Brag lets you start with
£100 which you put into
the pot and your cards are
dealt. Then it is for you to
decide whether you fold,
brag — raise Ihe stakes —
or pay to see the computer
hand, The ZX-81 has the
same options and the pot
may soon become substan-
tial. The rules are simple
and the game addictive bui
if you decide that the
computer is cheating,
please do not shoot it, as
that is extra ventilation it
can do without,

The second program is
the American dice game
Craps, which also has
KimplB rules and high
stakes. One to fourplayers
or shooters can pit their
nerve against the random
fall of the dice, taking it in
turn to try to make a
natural while avoiding
snake eyes, which is craps
— and von though!

computer jargon was
complicated?

The programs have
excellent full-screen
graphics and cost £5.50
and £3. 95 respectively,
from Newline, 8 Hwell Rd,
Wollatan. Nottingham
NC8 2DE.

16

SINCLAIR USER August JFtttf

ENHANCE YOUR StNCLA/R ZX8V

Video Inverter adds
professional touch

Displays sharp, white characters on solid black
background TV screen.

A toggle switch lets you choose between NORMAL
and REVERSE,

NEW
ORDER NQW1

KIT £4

READY BUILT £S

(VAT, TOP irtft.l

A small printed circuit board fits on top of the logic
chip inside your ZXS1 .

Comprehensive, easy to follow, step by step
instructions make the modification a simple task.
We will fit your inverter to your ZX81 for £7.50,

For convenience print your name and address on back
of your cheque or postal order and send to:

D. FRITSCH,

6 Stanton Road,

ThefwaH,

Warrington

WA42HS

NOW FROM AFDEC

ZX81

RAMPACKS

16K

£25.00

Inclusive and post free.
Well proven design. Simplicity itself - Justpluginand
go. Power derived from ZX81 without additional
connections.

Ingenious flush mounting design eliminates 'Wobble' and
accidental memory loss.
Special feature - LEO On/ Off indicator.
Coming soon - A professional keyboard at an affordable
price.

Send the coupon TODAY for your Rampack. Allow 14-21
days for delivery ,

AFDEC ELECTRONICS LTD, 318 Kampshott Lane
Basingstoke. Hants.

Please supply .... 16K Rampacks at £25.00 inclusive.
Cheque-'P. 0.. 'Money Order enclosed f. , , -

Please Print Clearly.

Name . . . . - h >

Address * . . . - * ■ *

ZX Spectrum

20 Programs £6.95

The ZX Spectrum has brought advanced
computing power into your home, The
Cambridge Colour Collection, a book of
20 programs, is all you need to make it
come alive-
No experience required. Simply enter the
programs from the book or load them from tape
(£2.95 extra) and run.

Amazing effects. All programs are fully
animated using hi-res graphics, colour and sound
wherever possible.

Entirely original. None of these programs has
ever been published before.
Proven Quality, The author already has 30,000
satisfied pu rchasers of his book of ZX81 programs.

Hours of entertainment

• Lunar Landing, Control the angle of descent
and jet thrust to steer the lunar module to a safe
landing on the moon's surface.

• Maze. Find your way out from the centre of a
random maze.

• Android Nim, Play the Spectrum at the
ancient game of Nim using creatures from outer-
space.

• Biorhythms. Plot the cycles of your
Emotional, Intellectual and Physical activity.
Some would say this is not a game at all.

Improve your mind

• Morse. A com plete morse-code training k it
This program will take a complete beginner to
R.A.E. proficiency.

• Maths. Adjustable to various levels, this
program is an invaluable aid to anyone trying to
improve their arithmetic.

Run your life more efficiently

• Home Accounts, Keeping track of your
finances with this easy-to-use program will
enable you to see at a glance where the money
goes and plan your spending more effectively.

• Telephone Address Pad. Instant access to
many pages of information,

• Calendar. Displays a 3 month calendar past
or future, ideal for planning or tracing past
events.

ORDER FORM:

Send Cheque or P.O. wish order lo>

Depl, D. ( Richard Francis Aitwasser, 22 Foxhollow, Bar Hill,

Cambridge CB3 8EP

Please send me

Q Copies Cambridge Colour Collect ion Book only £6.95 each,

D Copies Cambridge Colour Collection Book ft Cassette

£9 90 each

Name;

Address:

SINCLAIR USER August 1982

17

AUTOMATIC

ZX " TAPE CONTROL

The logical extension for £59.95

the Sinclair ZX8I giving

data retrieval & word processing

The ZX99 Tape Control svstem is a sophisticated extension to
the Sinclair ZX81 Microcomputer, providing remarkable
additional capabilities,, which allow both the beginner and
expert access to a professional computing system without the
expected expense.

DATA PROCESSING

The ZX99 gives you full software control of up to four tape
decks (two for reading and two for writing) allowing merging of
data files to update and modify them. This is achieved by using
the remote sockets of the tape decks to control their motors as

commanded by a program.

* PRINTER INTERFACE

The ZX99 has a RS232C interface allowing you direct
connection with any such serial printer using the industry
standard ASCII character code (you can now print on plain
paper in upper and lower case and up to 132 characters

per line.)

* MANY SPECIAL FEATURES

There are so many different features that it is difficult to list

them all:

For example:

AUTOMATIC TAPE TO TAPE COPY: You can copy any

data file regardless of your memory capacity (a C90 has

approx 20QK bytes on it] as it is loaded through the Sinclair

block by block.

TAPE BLOCK SKIP without destroying the contents of

memory.

DIAGNOSTIC INFORMATION to assist in achieving the best

recording settings.

♦ TAPE DRIVES

We supply (and guarantee its compatibility) a Tape Drive
that works with your computer.

* COMPUTER CASSETTES

We supply quality (screw assembled) computer cassettes.

Please enquire for any not shown:

The ZX99 contains its own 2K ROM which acts as an extension
to the firmware already resident in your 2X81 'S own ROM. The
ZX99's ROM contains the tape operating system, whose
functions are accessed via Basic USR function calls. Each
function has an entry address which must lie quoted after the
USR keyword. All of the functions can be used in program
statements, or in immediate commands (i.e. both statements
with line numbers and commands without them}.

There is an extension board on the rear to plug in vour RAM
pack (larger than 16K if required). The unit is supplied with
one special cassette lead, more are available at £1 each
(see below).

COMPREHENSIVE USER MANUAL
INCLUDED IN PRICE

^ Z X99 SOFTWARE j|fr

We now have available "Editor-99 ', a quality word processing
program including mail-merge, supplied on cassette for £9.95.
Also, following soon will be:

* Stock Control * Order Processing

* Sales Ledger * Debtors Ledger

* Business Accounts * Tpx Accounting

CQMPU TEH CASSETTES

QTY

Mice

TOTAL

ITEM

QTY

PRO

PS.P

TOTAL

QRDEH FORM TO

dota-o/zette*

C5

2Sp

CASSETTES

Sm left

CIO

J7p

ZX99

59 vS

295

Dept SU4

CI2

3Bp

E312 Tope Dri»*

2A 00

100

44 Shfoton Sjhree'

London NW1 AUG Tel: 01-2S8 04 09

Telephone trnawi'*! wekome

CIS

3°p

EDITOft-99

9-93

SO

C;U

41p

CASSETTE LEAD

1 oo

lo

CIS

Op

Cheque,

PQ poyofal* Ir>&rorkr0>* {<\d

HAMi

C30

Mp

|

■»3

■ or

ADDRESS

3 , 10%F>&P

Add mm £ t 50 1

SIGNED

IB

SINCLAIR USER August 19H2

news

Colour for

Scisoft

maths

ANNUAL subscriptions
for Sinclair User and
Sinclair Programs are
among prizes being of-
fered in a competition for
the under-1 Is. The winner
will be the child who does
the best colouring of the
cover of the Jungle Maths
cassette which is produc-
ed by Scisoft, the educa-
tional software house,

The competition is being
run jointly by Scisoft and
Microware. the Leicester
software and hardware
retailer. As well as the
subscriptions, the winner
will receive a Microware
voucher.

Entry forms will be
given with a copy of the
cassette. Entries close on
September 30 and the win-
ner should be announced
in the December issue of
Sinclair User.

16^

4»WMMJ4

y Northern fair
'a disaster'

MiJtF Johnston

THE FIRST computer fair
for hobbyists to be held
outside London was a ' "dis-
aster"- That was the
verdict of the majority of
exhibitors at the ZX
Mi cr of air in Manchester.
A variety of reasons
were advanced, including
the visit of the Pope to
Manchester the following
day: 'the bright warm
Bank Holiday weather': it
was held at the wrong time
with the Spectrum hang-
ing over the market; and it
was staged at the wrong
venue with the New
Central Hall being on the

wrong side of the city,
where parking was a
problem. The result was
that 2.000 people visited
the show and spent little
money there.

"1 think it reflected the
state of the market and
there were a few things
which went against it."
said the organiser, Mike
Johnston. "We had about
2,000 people compared to
between 5,000 and 6.000
at the London shows but
we are not talking about
the same catchment area
and if we had held it only
on one day, the attendance
would have been
reasonable '.

A major criticism from
exhibitors was that the
show had not been given
sufficient publicity. Sue
James of Microware in
Leicester said that in her

ZX-81 taking off in the States

THE ZX-B1 is beginning
to take off in the States.
An agreement between
Sinclair Research and the
American Express credit
card company has
resulted in a flood of
orders for the machine.

The credit card com-
pany sent a direct mail of-
fer to its two million card-
holders in the U,S. at the
end of May. In what
Sinclair Research calls "a
very positive response",
2,000 orders were receiv-
ed by noon the day follow-
ing the offer. In the first
three weeks more than
25.000 orders were sent to
American Express.

Total sales from the of-
fer have been forecast at
50.000 units and it is
thought that may be a con-
servative estimate.

The offer was agreed
between American Ex-
press and Sinclair
Research following a suc-
cesful test marketing for
the ZX-81 at the end of last
year. The test market had
been requested by the
credit card company.

The deal does not affect
the plans by Timex to
market its enhanced ver-
sion of the ZX-6L the
Timex Sinclair 1000,
which has a 2K RAM in-
stead of the normal IK.

That will not be on sale un-
til this month and Sinclair
Research in the U.S. is con-
tinuing to sell the ZX-fll
until the Timex sales reach
a certain level.

Sales of the ZX-S1 were
15,000 a month in the U.S.
in the early part of the year
and it is estimated that
435,000 have been sold
throughout the world.

Sales in Britain declined
in April but are said to
have recovered in May.
The machine is being pro-
moted in new markets.
Sales are going well in
France and reasonably
well in Germany and in-
creasing in other markets.

company's advertisement
in Sinclnir User in June the
Manchester Microfair
was mentioned and the
company had received
many calls from people
who had not known about
it.

Johnston replied; "It
received the same amount
of coverage as the
previous London shows,
when we were criticised
for having too many
people."

He added that he had
not been deterred from
organising fairs and would
be holding another.

The experience of Man-
chester does not appear to
have influenced com-
panies unduly from exhibi-
ting at shows nut suit:
London. The next two pro-
vincial shows were both
reporting a high level of
interest.

Gordon Hewit, a com-
mittee mernher of the
Edinburgh ZX Computer
Club, which held a fair in
July said that many exhibi-
tors disappointed with the
Manchester show End
turned tci Ihem in the hope
of doing better,

They see Scotland as a
more fertile area and. with
Edinburgh being a good
cent re of communications.
we can attract people from
all over the centre of
Scotland/' he said.

On the same weekend
Microfest 82 was held in
Manchester. One of the
organisers, Dave Hewitt,
said that many of the
people had wanted to take
space because it sonmod 1o
be better organised.

SINCLACRUSER Auf>ustim2

lfl

Spectrums six weeks late

ALMOST two months after
the launch in a blaze of
publicity at the Earls Court
Computer Fair in April.
Spectrums at last were
being delivered in June.
The delivery dates being
quoted at the launch were
a confident two weeks for

the first orders. According
to Sinclair Research, the
initial delay was caused by
the time needed to have
production running
smoothly.

When the first batch of
16K machines was ready
eventually for despatch at

Lending software

"1

A NEW software library
has been set up to allow
Sinclair users to take ad-
vantage of the many items
on the market without hav-
ing to buy the cassettes.

Membership of the
Sinclair Owners' Soft-
ware Library costs £5,
which includes the hire of

the first cassette, Subse-
quent tapes can be hired at
El for three weeks.

A quarterly newsletter
is also sent to all members,
with details of new addi-
tions lo the range, The sub-
jects covered include
games, educational and
toolkit programs.

about the beginning of
June, a design fault was
discovered. No-one is
saying what the fault was
hut Bill Nichols, Sinclair
Research public relations
officer, said: "It was a
very obscure fault which
would not have shown up
80 or 90 percent of the
time,"

Once that had been
dealt with, there was a dis-
tribution dispute atTimex,
NitiholJs added that delays
of between six and eight
weeks were likely for
people whohadnrde red by
the first week in June,
After that, delivery should
be down to the standard 2B
days.

Sale may
raise £10m

SINCLAIR Research has
passed the first hurdle in
the planned sale of shares
in the company, It has
passed the preliminary
audit commissioned by the
merchant bankers, N M
Rothschild, and the sale is
expected in the autumn.

Rothschild is arranging
the final details, which are
likely to involve selling to
chosen City institutions 10
percent of the company. It
is expected to raise at
least £10 million, which
would put a valuation of
£100 million on Sinclair
Research but the figure
raised could be £20
million.

>

>

>

^jcS^^Jv'm^KBSS::^:^

PERSONAL SOFTWARE SERVICES, 112 OLIVER STREET. COVENTRY CV6 5FE.

ZX-81 OWNERS - YOU CAN NOW

LOAD/SAVE 16K IN 26 SECS

WITH THE INCREDIBLE QSAVE PACKAGE FROM PSS

* Verify successf ul saving of programs * Compatible with your existing recorder
*No hardware modifications needed *No extra power supply necessary
*No more wasted time waiting for programs to load or save

QSAVE comes in two parts: A HARDWARE - simply plug the QSAVE amplifier/filter between your existing tape reader and
the ZX81 (all leads supplied).

B SOFTWARE - Load the QSAVE cassette before you load a tape or key in a program. You can
then save & reload a full 16K (including RAM TOP) in only 26 seconds, i.e. a data transfer rate of 4000+ BAUD compared with
only 250 on the standard ZX81 .

QSAVE also gives your 2X81 a verify functton just like the Spectrum which allows you to check that your programs have saved
property.

REVOLUTIONISE YOUR PROGRAMMING NOW FOR THE ALL INCLUSIVE PRICE OF £14.90

Make cheques, P/O's payable to PSS. Futl money back guarantee. Normal delivery within 7-14 days.

ZX SOFTWARE FROM PSS

We also have the widest range of high quahty software faf the ZXS1 available anywhere. Whatever your needs we have the program for you .
From a superb version of PUC K IVI A N to a Compiler or a comple M wurdprocessor package you need took no f u rther than PSS . 1 n addition
all of our software is available rhr OMgh the ZX Software Library. For a once only payment of F5. 50 y ou can have any five of our packages I E 10-00
for tenj . You take one taoe at s lime and make vour own conies - saue vourself f 's nn 1st r.™-« KAF tnr f..N H^taik

<

take one tape at a time and make your own copies - save yourself £'s on list prices. SAE for full details,

20

SINCLAJRUSER AiiunsI VMZ

letters

Contest too difficult

I AM writing to complain
about the competition in
your June issue. What
annoys me most is that the
amount of people entering
this competition is limited
to those who have a fair
amount of knowledge about
electronics and com-
puters, and that must
surely be a small per-
centage of your readers.

As this is a magazine for
all Sinclair users, surely a
competition which every-
one could enter would be
more appropriate?

Admittedly, the Spec-
trum is an outstanding
prize but if it is so good,
why not give everyone a
chance of winning one?

Despite the complaint. I
think your magazine is
excellent, so continue the
good work*

Philip Morris,
Langford. Nr Bristol

• There are two reasons
why we decided to base
the June competition GUI a
hardware application. The
previous two had been for
software and we though t it
better to set something for
those with an interest in
hardware. Second, we do
not share your view that
people with a knowledge of
the electronics of com-
puters comprise only a
smaU percentage of our
readership.

Character
error

HAVE YOU noticed that
CHR$ 7 and 135 are
printed as the same chara-
cter in the ZX-81 manual

and that the graphics
character on KEY 3 is
missing?

I have found out that the
missing character has the
code 135 and that the one
printed is wrong. The
character with code 1 35 is

Mark Colson,
Horncastle, Lines.

Misprint
problems

SEVERAL MONTHS ago I
finally bought a ZX-Bl and
promptly set about
mastering the manual. All
went well until I reached
page 129, Exercise 4,
prophetically entitled
"This one will drive you
mad' ' . Try as I might, every
time 1 entered the program
and tried to run it, 1 would
be greeted with error code
5/90 or 5/150, or 5/210 if I
pressed l *Q*\

After some thought, it
occurred to me that the
lines of the program the
machine was trying to
execute when the report
codes appeared were all
PRINT statements. That
meant the machine was
trying to execute those
commands but had
insufficient screen space
to do so.

The next thing which
occurred to me was that a
SCROLL instruction had
gone wrong somewhere, so
1 1 he n se t a bo ut j a mming-in
extra scroll statements
where I could- Finally. 1
found thai 42 SCROLL
made the program work-
When I wrote to Sinclair
to point this out, the

answer arrived with
commendable speed to the
effect that there was a
printing error in the
program and that line 40
should be terminated with
a comma. In fact, that
makes the program run
much prettier than my
alteration.

The point is that I have
never seen in your or any
other publication any
reference to the error and
that is curious — because
250.000 people have not
noticed it. or 250,000
people have ignored it. or
250,000 people have
achieved such a level of
programming ability by
page 129 that they thought
it beneath them to draw
attention to it.

The reason I am writing
is to pose the question if
there are other misprints
of which we are unaware?
At the very least, I think
that it would be very user-
friendly of Sinclair to mail
a list of errata to all pur-
chasers, so freeing people
like myself of a good deal of
head-scratching.

Finally, a good test of
pocket calculator

accuracy over a series of
functions is to find the Sin
of 45 degrees, then find the
Co3.Tan ArcTan, ArcCos
and ArcSin of each
successive result, hoping
that it will yield the
answer 45 degrees again.
In my experience, Casio
calculators, for example,
yield an error of half a
percent while Sinclair
calculators yield an error
of 33 percent. Try it on the

ZX-81. using a program of
the kind 10 INPUT A, 20
PRINT A, SIN A. 30 LET
B = SIN A. 40 PRINT B,
COS B and so on. Note that
45 degrees must be
converted to Pi/4, as the
ZX-B1 works in radians,
and 45 cannot be handled.
Try a few values and you
will he amazed and aghast
alternately at the results.
MP Campbell,
St Ives, (iambs,

RAM pack
price falls

l AM writing about
Sinclair User June, 19B2.
On page 5 you state that
the Sinclair RAM pack has
been reduced to E30. On
page 10 you say the cheap-
est RAM pack is that of
AVC Software at £32,50,

On pages 20. 42, 54 and
60. you advertise RAM
packs for less than £30.

David Clifton.
Beckingham,

Doncaster. S- Yorkshire

Searle
corrects

THE JUNE issue of Sinclair
User contained an article
about me by Elspeth
Joiner. The article was
based largely on an inter-
view conducted on April 7,
1982, prior to the launch of
the Spectrum personal
computer. In the article 1
am quoted as saying thai
Sinclair Research Ltd will
launch another small
computer this year. I was,
in fact, referring to the
then imminent ZX
Spectrum.

Sinclair Research Ltd
has no plans to announce
new personal computers
in 1932.

Nigel Searle,

Head of Computer Division,

Sinclair Research Ltd.

Cambridge

S1NCLAIKUSER August 1982

21

ZEDXTRA

BEAT THAT HIGH SCOREI
GOBBLE THOSE DOTS
BEFORE THOSE MEANlES
GOBBLE YOU! YOUR ONLY
AIDES ARE FOUR "POWER
PILLS" WHICH MAKE THE
MEANIES EDIBLE- BUT
NOT FOR LONG I

• MACHINE CODED FOR FAST ACTION
•EXTRA "GOBBLER " FOR 10.000 POINTS

• ONSCREEN SCORING

• high scone with "enter name" facility

• UP TO 4 PLAYERS

AN ANNOYINGLY FRUSTRATING GAME FOR ONLY £5,95

STAY ^LIVE *S LQHQ AS POSSIBLE IN QPtiH SPACE FILLED WITH FLVlNG ROCKS
5COfl E H V 3 H DQTIHG TH E M WH ICH A.L5Q CAU5 ES THEM TO BR EA K I NTO LOTS
OF LITTLE BITS AND MAKES LIFE EVEN WORSE'

• MACHINE COPCD FOR
FAST ACTION

>□» Screen itORiNG

• HIGH SCORE WITH
'ENTER NAMC FACILITY

•UPTO* PLAYERS

*EXTRA SWF FOR 1,*M ITS
IH(i1 AS EASY A5 IT
SOUNDS 1 1

■SHIP MOVES JUST LIKE

AR CACHE VERSION
*ROTATE LE.FT.iHQT ATE
PIIGhTi'TmRUST

• FIRES IN A118
DIRECTIONS

• INCREASING NUMBER
OF ASTEROIDS

• THHF-r ASTEROID SIZES

• -NASTV ALIEN SPACE-
SHIM FIRES BACK!)

THIS GAME (S JUST AS BAD - AND ONLY £5 95
AN OFFEH FOR REAL MASOCHISTS - BOTH TAPIS FOR £9.95

MAIL ORDER ONLY-PLEASE MAKE CHEQUE/PO PAYABLE TO

THE SOFTWARE FARM
CRAIGO FARM, BOTANY BAY, TINTERN, GWENT

IVI n ! L. «.

ji_ r_ i k_

COMPUTER

ACCESSORIES

BOURNEMOUTH'S NEW SOFTWARE
OUTLET FOR SINCLAIR COMPUTERS

GAMES - BANK ACCOUNT - EDUCATION - MULTIFILE
ADVENTURES KEYBOARDS • GRAPHICS fl-O.M.S
RAMPACK5 CASSETTE RECORDERS BLANK TAPES

ZX81-XTREK1J— £4.95

THF LJL TMATE SPACE GAME FOR «( RJLL SCREW GRAPHIC DBHAY
Control your starship across the galaxy destroying the enemy w«ti
your photon torpedoes and phasera but bewar#ir>e enemy ratBitateH
Can you uuiwn them.

At the touch ol Akey Scan [he galaxy at long and short range to. plan

your strategic moves- The screen is rilled with the quadrant you ere in
and give fuil statue of your energy: force shield . quadrant uuml i wi
time in star dates: photon torpedoes; quadrant sector.
A very fast gams!" Full doCuman tatlon wflnch includes sample game

ZX SPKCTRUM CHARACTER PB<XRAMMKR £5.S0

Programme your user definaWs characters or screen with the

character programmer Vuu can def me characters using a X04 Mem*
with Full cursor connote.

This toai is a must lor all programmers . Allows you to define your

characters with no prohfemsl ! See your characters ttfk* shape as you
define themi Facilities include; Editing s-Kislirtg character, clear
character, rtef rr»e new chM&ctw, defms character using binary codas,
define character using decimal codes, sawe character set to tape,

Supplied with over 60 sample characters.
ALSO STOCKISTS OF LEADING BRANDS.

Please send me . . . . KTfigK Hat fa 95 each
- , ZXCPatESSOeaeh.

I enclose cheque lor E

Cheques/ postal order? should be made payable to ZEDXTRA and

crossed / ' account payee.

ALL ORDERS WILL BE DESPATCHED BV RETURN
For further information contact

TEL: NOfttHBOOfWE(020t6}2498

X81

users

I need more memory! please rush me the fully
assembled, tested and guaranteed

'BYG BYTE'

16K RAM PACK

Name ....... , - —

Address - - „...„,„,..........

Make all cheques & PO's payable tor-
Phoenix Marketing, Oaklands House Solartron Road,
Farnborough, Hants. Tel: (0252) 514990

FULLY INCLUSIVE PRICE _ su

£25.00

22

SINCLAIRUSER August 1932

nemOTECH Explores the
Excellence of your

ZX81

■■■■■■•■■■■■■■■■■■■■a

■Sri ■"■

■■' i5r !■■■■■■ ■■■■■■■■•■■■■

mm ji J| ■■■■»--■■■■■■■■-■■-■

memotechfc Plemopah Banqe

All five of the currently available Memopaks are housed in elegant black anodised aluminium cases, and are slyled to fit wobble f
All five of the currently avaiiaoie ^ e ^p ^ ^^ ^ ^ ^ ^^ Memo , ech or Sinclair) to be connflcted .

ree

plus U AT

437 Z6

plusUBT

pIusUflT

MEMOPAK 64K MEMORY EXTENSION

The64K Memopak extends the memory of the ZXBt by 56K, and with theZXBi gives 64K, wh.ch is neither

switched nor paged and ia directly addressable. The unit is user transparent and accepts commands such

Breakdown of memory areas. .0*8K-Slnc lair ROM. 8-16KThls area can be used to hold machine code for

communication between programmes or peripherals 16-64K A straight 4BK for normal Basic use.

MEMOPAK 32K and 16K MEMORY EXTENSIONS

These two packs extend and complete the Memotech RAM range (for the time being !) A notable eature of
32K pack is thai it will run in tandem with the Sinclair 16K memory extension to give 4BK RAM lolai

MEMOPAK HIGH RES GRAPHICS PACK

HRG Main Features - - Fully programmable Hi-Res (192 x 248 pixels) * Video page is ^£ m *™ry and I bit
mapped and can be located anywhere in RAM • Number of Video pages is lim.ted only by RAM s.ze (each

takes about 6.5K RAM) • Inslant inverse video on/off gives flashing characters -Video pages i car i be

superimposed • Video page access is similar to Basic plot/unplot commands * Contains 2K EPROM monitor
with full range of graphics subroutines controlled by machine code or USR function

<

MEMOPAK CENTRONICS TYPE PARALLEL PRINTER INTERFACE

Main Fpatures - ■ Interfaces ZX8I and parallel printers of the Centronics type • Enables use of a range of dot
™ nxand da?sy wheetpHnters with ZX8, - Compatible with ZXBI Basic, prints Irom LLiST, LPR.NT and COPY
Contains firmware to convert ZXBI characters to ASCII code * Gives lower case characters from ZXBI mverse
character set . .^ >*

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SINCL A TE US ER A u*u st 1 932

23

T!

HE IDEA of data code com-
pression is certainly not new,
as it has been used in various
forms for a long time in mainframe
computers. The process of
increasing the number of valid and
unambiguous data characters
which can be stored in a given
memory area can be achieved either
by reducing the number of bits used
to describe each data character —
i.e., by changing the character
codes or by reducing the number of
redundant and insignificant data
characters such as space
characters.

The routines described are one

Getting a quart
into a pint pot

DJ, Todorovic considers data code com-
pression by changing character codes

example of a former approach on
the ZX-fll but with practical value
on machines with more than IK of
RAM.

As it is true for all compression

10

2tf
25
3©

se

80
90

100
110
120
ED:
130

REM #*ZX31 TEXT COHP^CTER**

rem c gtn i<sae

i_ ET K = 1

INPUT T$

IF T£="BVe** THEN STOP

PRINT "TEXT.* ";T*

GO3U0 3100s

IF K>0 THEM GOTO 11*

PRINT "ERROR ",T$

PRINT TH9 J& + &*£.* ; "GRRRtt JO

GOTO 30
GOSUB 320S
PRINT LEN C-*;
. C$

PRINT LEN T$;

14-13 GOTO

OH - COHPRES5
iC.tt* EXPANDED

ROUTINE**

SPACE J "
STEP 3

& ■'. S4-> -3-

+C

30
3000 REM * ^COMPRESS
3U0S FfiST
3010 LET C% = '"
80213 LET T*=T$+" ("DOUBLE
6030 FOR C=l TO LEN T$-2
30A0 LET X=0
3050 FOR S=0 TO S
3030 LET K =COC'E T* l"B+CJ
8070 LET K=l+K» fS>2S SN&
S* <K < >0Ji

3030 JF K<=0 THEN RETLfRH
3090 LET >;=X + K*4-0**S
8100 NEXT S

3110 LET C$=C*+CHRS VXV2STS + - 5J
HR$ (X-256*IWT fX/fiF6> )
3120 NEXT C
512S SLOW
3130 RETURN

5200 REH * -3 EXPAND ROUTXNE**
8205 FBbT
saao LET T$ = ""

8S20 FOR C = l TO LEN OS STEP £
3236 LET X=2Sf5*CCM>E CffCUDuf-E
* (C+l>
3S4.S LET
8£50 LET
8261c! LET
3270 LET
8280 LET
1-1) +CHR$

CX3+24 RND X3-I
3290 NEXT C
3295 3LOU
S300 RETURN

X3 = INT f X .»• 1300.1
X = X -X3*1600
X2-XNT f.X..'4-O.l
X X ~ X - X 2*4-0

T*=T$+CHR$ lXi+24 RND X
I X2 *2* RHD X2 - 1 .> * CHR *

methods, there must be a kind of
trade-off. In this case, besides the
increased processing requirements
due to the existence of compactor
routines, there is also a serious
restriction on usable character set:
usable set is limited to 39
characters, including letters A-Z.
digits 13 -9, two special characters —
comma and period — and a space.
All other characters, including
special, graphic and inverse
characters, are illegal and are
flagged as such if submitted to the
compression routine.

On the other hand, compactor
routines are providing the compres-
sion ratio of 2:3, so the compressed
text will occupy ooly two-thirds of
the area required by the original
text. Bearing in mind character-set
limitations, the routines either may
reduce the required memory area or
provide a 50 percent increase of
usable text length.

As the space savings should be
greater than the space occupied by
compactor routines — 314 bytes for
compress and 282 bytes for expand
— the approach is beneficial only an
larger amounts of text data — more
than 2.000 characters — as such
programs compactor routines might
improve significantly the space
utilisation and increase the amount
of text stared.

The test program shown in figure
one, up to line 140, is only to demon-
strate compactor routines and to
print the results after each step. It
will solicit the input string text and
the operation may be terminated by
inputting "BYE". It also contains a
small error routine, which is used
ooly if the input text contains an
invalid character — - i.e., return
from compress routine with

24

SINCL A IK USER Auj; u.sl 1 W2

compactor
routines

variable K not greater thanO. In that
case input text is printed with the
invalid character flagged under-
neath with an inverse "f*\

Routines for text compression at
HneflOOO and expansion at line B2Q€
are both designed to operate in
FAST mode and revert to SLOW just
before returning to the main
program. By omitting lines 8005,
B125, 8205 and 8295, the oper-
ational mode of these routines will
be as set in the main program. Com-
pactor routines use the following
variables:

7$ __ string which contains the
original text, as an input for
the compress routine, or the
expanded text, as en output
from the expand routine.
C$ — string which contaios the
compressed text as an output
from the compress routine or
an input for the expand
routine. Note that PRINT of
this string may be unreadable
and look longer than the
original text, depending on
the bit pattern obtained in the
compression, which may
produce any of the ZX-81
character codes,
C — current token position within

the original text.
B — current position within a text
token — three characters
from the original text.
K current valid character code.
There are 39 valid characters
mapped starting from 1 for
space and values 2 to 39 are
assigned for ZX-81 charac-
ters from comma to Z. Values
equal to or less than zero are

returned to the main program
if the compress routine en-
counters an invalid character
on position B + C from the
start of the original text. Note
that this variable must be pre-
set to 1 in the main program —
line 25 — before calling the
compress routine to cope with
empty input text.
X. XI, X3. X3 — used in the trans-
formation process to cal-
culate character codes.
The 0.5 offset which is used in line
8110 is to provide the correct
rounding-up for the CHR$ function.
Also note in line 8280 the use of logic
AND, which would provide expan-

characters, which therefore are
declared as a valid set for com-
pactor routines.

To optimise the transformation
process, more-often-used charac-
ters should be placed at the
beginning of the string SS. String 5$
as defined on line 26 of figure two is
using the same valid set as the
routines from figure one. There are
also some changes in the compress
and expand routine but the solution
from figure two would require the
definition of the string S$ in both
programs, if the compress and
expand routines are used in
separate programs.

The idea of text compacting as
shown in figure two might be en-
hanced and the valid character set
enlarged by making S$ the string
array. Of course, as we need some
additional indexing within that
string array which will enable
switching from one string array
element to the other, it will be at the
expense of the compression ratio,
which will be less effective.

The routines can be used to
compress text data which is to be
stored together with a program on
the cassette and are therefore very
usable in programs handling direc-

9RBC

3060
3070

e©QA

aeee

X3)

LET 5*=-' {5PftCE,i "+"131^345573
DEFGH I JKLHMOPORsTU f JUXV2 , . "
IF K, ;4-0 THEM GOTO 110
FOR K=l TO 33 „-„--.

IF T#CB+Ci »S*<IO THEN l-OTO

HEXT K

RETURN __. _„. .

LET T$=T*-r3$ 1X311 +^$ (XSJ +'^* l

sion with 1 mapped as a space
character. Use of the logic function
is also obvious in line 9070, where
different non-contiguous velues are
assigned to variable K.

When the character set is not
entirely satisfactory there is a
possible modification, shown in
figure two. This is the solution used
normally on ASCII-coded machines
— remember thai ZX-81 is oot —
and involves the use of a conversion
string SS, That is a user-definable
string which also contains 39
characters — as the previous res-
triction still holds — but it is
possible to put in any combination of

tones and indices. It is also possihle
to handle in a similar way the read-
only text as, after entering it, com-
pressing and storing in arrays, such
programs do not need the compress
routine. So before such a program is
saved on the cassette, the compress
routine may be deleted, as in normal
use the program will need only the
expand routine to prepare the data
to be PRINTed.

Resides further savings in
memory space, this method provides
additional security benefits, since
the LOADed program will contain
text data which cannot be modified
easily without the compress routine.

S INCL A LR USER A uf>usl 1 982

25

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You can even sell your micro or pick up a bargain at the bnng-and
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26

SINCLAIR USER August ISH.2

starting from
scratch

Come to the ZX-81 with a clear mind to
make the best use of your new machine.

Lifetime's obsession can
easily be acquired

BUYING a ZX-81 can be the
start of a lifetime obsession
with home computing. It is
easy, however, to become
discouraged if every thins does not
go to plan from the beginning.

For those with only a little
knowledge of computers end their
capabilities, the best way to
approach the ZX-81 is to abandon
any ideas for specie! uses, While the
basic machine is ideal for learning
how to use computers, it is too small
for any major uses, it is better to
become accustomed to the many
facilities and then decide how you
wish to ue them.

Begin by unpacking the machine,
overcoming your surprise at its size
and weight end. following the
manual, set up the aystem. If you
cannot get the K on the screen,
check that everything is plugged
into its correct socket and re-set the
machine by pulling-out the power
plug for a second and try tuning-in
age in .If s till not hin g appears . chec k
the power supply unit by shaking it.
If it rattles, return it. If it is satis-
factory, check your system with that
of a friend.

Once the K appears you are ready
to begin learning about the ZX-81. It
can save family arguments if you
can afford a separate television set
for your system, It also makes life
easier if you can find somewhere to
leave your equipment set up per-
manentiy. You will find that a few
power sockets are needed and a
four-way block connector on a short
length of e x tension c abl e w ill hel p to

StNCLAlRUSER Au^uM \W2

tidy trailing leads.

The manual is written in great
detail and is reasonably easy to
follow, Some of the chapters may not
seem immediately relevant but it is
worthwhile reading them as you
might miss something which is
important.

Patience is needed at that stage to
learn the ways in which the
computer will accept information. It
ik tempting to try to enter programs
before you are really ready but thai
is likely to leed to errors. For
example, words like AND, THEN,
and AT should not be typed-in letter
by letter. By the time you have
reached chapter 11, you should
have accumulated sufficient know-
ledge to be able to type-in other
people 1 s programs, such as those in
Sinclair User and Sinclair Pro-
grams, without too much difficulty.
It is important that when using the
machine it is not jolted. Some of the
connections can easily work loose
and everything which has been put
in will be lost.

The manual is not to everyone's
taste and if you find it difficult to
follow, a number of books on the
market can help you. Find the one
which suits you best.

As a way of relaxing, you can buy
some of the growing range of
commercially-produced software.
That can be loaded directly from
cassette but make sure that your
machine is big enough to take the
tapes you buy. There are some
programs for the unexpended IK
machine but most of them require a

16K RAM pack. The tapes vary in
quality. It is advisable to read the
reviews in Sinclair User and use
your judgment to find the best.

An alternative method to learn
about the ZX-61 is to plunge in at the
deep end and see what the computer
will do, Refer to the manual when
you have difficulties. You can ignore
the functions and calculations
initially and experiment with PRINT
statements to obtain the feel of the
machine.

You may have heard already
about the problem involved in
SAVEing and LOADing your own
cassettes. The manual again gives
detailed instructions but many of
the early machines would not
accept tapes from some recorders.
That problem is said to have been
overcome but there can still be diffi-
culties.

They usually occur when
LOADing tapes recorded by other
people. One simple method to over-
come this is to wind the tape to the
middle of the program and type
LOAD" " followed by NEWLINE:
then slowly increase the volume of
the recorder with the tape running
until the television screen shows
four or five thick horizontal black
bands. If you then re-wind the tape,
the program should LOAD normally.
Finally, a health warning. Apart
from any practical uses, computing
with your ZX-81 can be a very enter-
taining hobby and is almost
certainly habit-forming, You may
easily find yourself crouched over
your machine, red-eyed, in the early
hours of the morning thinking that
in another five minutes you will sort
out the problem.

Try to break that habit by getting
into the fresh air and meeting other
Sinclair users,

By obtaining a ZX-81 you find that
you have joined a not very exclusive
club with many thousands of
members, many of whom would be
only too happy to advise you if you
have difficulties.

Make sure of your regular copies
of Sinclair User and Sinclair
Programs and you can be guaran-
teed many happy hours with your
Sinclair machine.

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26

SINCLAIR USER August 19fl2

toolkit
routines

Phil Garrett looks at routines which can
assist in writing tidier systems.

Basic toolkits can help
put polish on programs

WHEN 1 discussed reviewing
ZX-B1 utility programs
with the editor, he was dis-
appointed that all the debug
programs operate only in machine
code and that the Basic programmer
is left to sink or swim. While it is true
that there is nothing available to

can be annoying, especially when
you forget to do it*

Renumber takes IK and a USR
call re-numbers your Basic program
in steps of five, starting from 5,
Other values for the step size and
starting number can be POKEd in and a routine to copy bytes from one
and it will always re-number to the place to another. More useful are

To return to the Hewson
Renumber, computed GOTOs and
umps to non-existent lines are high-
lighted in reverse video after re-
numbering. The arithmetic
expressions — e.g., GOSUB
1000 + INT (10*RND+1) — can
appear rather distorted, so it would
be as well to have a copy of the
original program to which to refer.

Hewson' s Prog rammers' Toolkit
requires 3K above RAMTOP and
includes routines to copy or delete
blocks of Basic lines and a number
of machine code monitor functions.
The re-number works in much the
same way as the previous program,
except that an end number can also
be given; the numbers are prompted
for, rather than having to be POKEd
in. The Toolkit seems to consist
mainly of lines of Basic starting from
9000, which are added to your own
Basic program with a USR call. RUN
9000 will then run the Toolkit, which
displays a menu of functions. There
is a hexadecimal loader and lister

Mp unrav* the ZL of orT^d T d of .h^ program Th^rou,™ took he fusions which oaa display^
neip uuiaveiuic u« «j ni „En D imnHotn™. line nnmhRrs nf hues containing a

logic in which my Basic programs
finish, there are several programs
which add extra facilities as they
are written, and can make them look
neater afterwards.

Even a program which is a jumble
of embedded subroutines and
GOTOs every other statement
looks weLUplanned when all the line
numbers increase in tens. Re-
numbering is probably the main
reason for the purchase of a toolkit
program and is the only function
included in every one at which 1
looked. The range of other functions
offered is very wide and some of
them seem to have been put in just to
make a program appear more sub-
stantial, rather than because they
are useful.

Hewson Consultants offers two
programs, a straightforward

about 50 seconds in Fast mode to re- line numbers of lines containing a

number 5K of Basic. particular string of characters or

A problem with which all the re- tokens you want to find — e.g.,

numbering programs have to cope computed GOTO 3 — and REPLACE,

somehow is the very useful but very which allows a string of characters

non-standard Sinclair GOTO — and
GOSUB. Our GOTO 1000+ 100* A
and GOSUB X are seen in f e w , if a ny <
other dialects of Basic, and are too

to be exchanged for another of
equal length. Both routines are slow
to execute.

I did not find the program very

'All re-numbering programs have to cope
with the very useful, but very non-
standard, Sincla ir GOTO and GOSUB/

sophisticated for a re-numbering
program to cope with, so have to be
tinkered with afterwards.

Another non-standard feature is
the jump to a non-existent line
number; Sinclair Basic simply

Renumber and a more sophisticated continues looking until it finds a line ad ° Q p u * *

robust; the hex lister did not work,
the re-number duplicated line
numbers when 1 set the increment
too large, and the program crashed
several times. The instructions for
both programs are brief, but
Renumber costs £4-95

Toolkit, Both can be used on ZX-81s
with either the standard 16K RAM
or with the increasingly-popular
48K and 64K RAM packs. They
require the user to re-set RAMTOP
before the program is loaded, which

SINCLAIR USER August 1982

whereas most Basics will stop with and Programmers* Toolkit £6,50

an error if the line does not exist. A
measure of the usefulness of a re-
numbering program is what
assistance it gives to the pro-
grammer in resolving those
difficulties.

The JRS Software Toolkit also
requires the user to re-set RAMTOP
and takes IK. A great deal has been
packed into that lK but ease of use

continued en p30

29

fJl

<i

continued /romp. 29

seems to have fallen by the wayside.
The re-number requires ell state-
ments such as GOTO 25 to be
changed to GOTO 0025 before it will
work. Computed GOTOs and jumps
to non-existent lines ere ignored
completely. Starting line and incre-
ment can be changed with POKEs
and the routine took eight seconds to
re-number 5K-

There is a search-and-list
function which could be used to find
all occurences of GOTOs and
GOSUBs, so that they could be
changed to the required format.
There are also search and replace
and memory left routines, plus three
graphics routines, Hyper graphics
mode alters the start address of the
ZX-81 ROM character table and
produces interesting but useless
effects; Fill fills a specified number
of lines with a chosen character;
and Reverse inverts as many lines
on the screen as required.

At £4.95 the program demands a
greet deal of care and effort from
the user, which surely is not the

mean a complete crash, not just stop
— if it encounters a computed
GOTO or jump to a non-existent line
number.

The other ACS cassette contains
Progmerge, which allows all or part
of a Basic program to be stored
above RAMTOP and then merged
with a second program, the whole
lot then being re-numbered. The in-
structions did not indicate what size
of program could be stored and a 3K
program I tried was too big. The re-
numbering, which can be run on its
own, has the same limitations as the
toolkit Renumber.

I was impressed with the ACS
assembler and disassembler
programs and so I was surprised at
the poor quality of its re-number
routine, which could be used only
with the utmost care. The instruc-
tions are clear, with helpful
examples. Progs tore/Toolkit costs
E7.50, and Progmerge £5.50.

ACS, however, has now brought
out Progmerge [version two) which is
said to have overcome the problems.
The program costs £5.50 and anyone

'ZXED is a most impressive program, fast
in execution, with clear and full
instructions and helpful error codes'

purpose for which utility programs
are intended.

The ACS Software Progs tore
allows a small — fewer than 2,750
bytes — Basic program to be stored
above RAMTOP. The program can
then be called, with USR, and acts
rather like a subroutine. Any varia-
bles used in the stored program
must already exist.

On the other side of the tape are
four small Toolkit progrems which
can be used with Progstore.
Hexloader and Hexlister are
obviously fillers and a waste of time;
no addresses are shown, so it is diffi-
cult to interpret what appears on
the screen. Progmod-l allows larger
programs to be stored above
RAMTOP by modifying Progstore.
Renumber works only in steps of 10
from line 10 and, incredibly, the
entire program will crash — and I

with the first version who wants it
updating can have it done by ACS at
a cost of £1 plus 25p for postage and
packing.

At4K, the dK'tronicsZXED toolkit
is bigger than the others and re-sets
RAMTOP automatically. The
program is controlled from six lines
of Basic 9990-9996 which are added
to your program with a USR call;
RUN 9990 starts the toolkit and
gives en inverse E prompt, waiting
for one of 1 1 commands. Whichever
is chosen, full prompts are given
and, if anything goes wrong, 10
special error codes will identify why
and where it happened.

Renumber prompts for start and
end line numbers, new base and
increment, ft then look<i through the
Basic and if it encounters a com-
puted GOTO it will stop with report
"Q/line no.". The user can then

insert a REM into the offending line
and continue with the re-
numbering. Impressively, jumps to
non-existent line numbers will be
re-numbered correctly e.g.. 5 REM
15 REM 25 GOTO JO will become 10
REM 20 REM 30 GOTO 20. It took
less than one second to re-number
5K of Basic,

Find will display the lines — not
just the line numbers — containing a
specified string, so it can be used to
find the REM GOTO X lines after re-
numbering, and Alter will replace a
string. Blocks of lines can be copied,
moved or deleted, stored above
RAMTOP and re-inserted into
another program, Bytes tells you the
amount of free memory remaining.

It is a most impressive program,
fast in execution, with clear and full
instructions, and helpful error
codes. At £6.95 for the cassette
version and £9.95 for an EPROM
version, it stands out from the rest of
the field.

Unfortunately I was unable to
load the last program, the Bug-Bytes
ZXTK and the replacement copy
ar rived too 1 a t e to be inc 1 u dad in this
review, which is a pity as it has some
unusual functions. Sniff displays
the file names of programs on a
ZJO-Bl tape — thet is useful if you've
forgotten them; Where gives the
address where a Basic line starts in
memory; Rem creates a REM state-
ment of specified length; Check
generates a check number to ensure
a program has loaded correctly, In
addition, it has Renumber — which
highlights computed and non-
existent line GOTOs — Copy. Move,
Extract — place above RAMTOP —
and merge blocks of Basic. ZXTK
costs £6,

Hewson Consultants, 7, Grahame Close,

Blewbury, Didcot, Oxon 0X1 1 9QE.

JftS Software, ra. Wayside Avenue, Wording,

Sussex 8N 13 3JU

ACS Software, 7, Lidgett Crescent, Rountinay.

Leeds LS8 1HN.

dK 'ironies, 23, Sussex. Road, Gorleston, Great

Yarmouth, Norfolk.

Bug Byte Software, SS-lOO The AJbarty. Old

Wall Street, Liverpool L3 SEP

30

SINCLAIR USER Autfusr IH82

programs

^

BAZOOKA

MANOEUVRE your Bazooka
with keys 1 and Q t and fire
at the oncoming tank wittyO
before it can nail you with its own
weapon.

A simple but effective game,
submitted by A S Gale of Exeter,
Perhaps its most distinctive feature
is that it manages to produce both
flicker-free graphics and an enemy
which fights back — and that on a
IK ZX-81 . Graphics notes:
40 — Graphic A
128 — Inverse minus. Inverse 0.

graphic 5, space.
150 — Inverse shifted M
190 — Graphic 4, graphic 2

199 — Inverse space

200 — Space, shifted M
240 — Inverse shifted J

400 — Asterisk, O t graphic A
500 — Shifted H
600 — Inverse BOOM

1(3 LETT R-PX^PX

30 LET C=PX-PT

30 LET S=C

4-0 LET e = CO&E M JflT

5© LET X=URL s IBS"

&0 LET Y=COOE 'COS "

7 LET 3=URL "50O"

100 CL5

10-5 LET F=INT £RND#CGDE «■*«)

li© LET G=OODE

126 PRINT RT F . G . '^S "

130 LET G = G-R

14.S IF G(=C THEW GOTO X

150 PR INT RT & -ft j C , ; " " ; RT G «-R * C

" " ; RT B ,C ; "B"

155 LET &=G

160 IF INREY*="1" THEN LET £=& -
i

170 XF INKEY$="Q" THEN LET B = B +

18©

190

■ '■ -|

310

P20

34-0
4.WI0

405
4-10

4.20
500
5 10
53©
600
610

XF XNi*EY$="S" THEN GOTO Y

IF XNT tRNiXCOOC: "j ") -CODE

HEN C05UG Z

GOTO CODE "M"

PRINT RT B.D,. " ►"

LET £> = t>+R

IF DiG THEN GOTO V

IF B = F AND D=G THEN GOTO Y +

GOTO CODE "fl"

PRINT RT F..G+R,;

PR INT RT F ., G 4-R.v

LET 5=5 -R

GOTO X

PRINT RT F..&-R; 1

IF F=B THEN GOTO

RETURN

PR INT RT 6 ,. € _:

PRINT S ; TfWKS H

Z+X

SINCLAIRUSER AugusM&62

31

16

NEXT N
PRINT *vr

XT GOTO 3-90

iS ?r? X 5fIa^TMEN^P«TNT RT 0,29..

Xl=Xl+dNKEY**"e"

3 - ( INK

3£ LET
=*** IF XKO THEN J-ETXiT^S

if ?P I tJl 2 g r T^lN^ET I W^T CRND

PRINT RT UjU.
?? wLs6 THEN

PRINT

w^ss;

ThUtEVfts-O" THEN LET
££ 5=1 THEN GOTO 1BO

!-=t FR-tu^HJ +<U=INT
1+3 K K i| 2 THEN N P§?fS RT H.G*Q

HIS IS a distinctly topical sub-
limit game, submitted by
M Thurston of Manchester, in
which a torpedo is dropped from b
patrolling aircraft and homes-m on
the cursor C, The cursor is mnn-
peuWsothBtildraw,thPtarpedo

into the path of the ™ b ™ ar 'f ._
Since the movements of three
separate points - submarine, air
craft and torpedo - • must bo co£
related a high degree of ski.
SvoSSd. In addition, the depr
he submarine varies by a random
value The graphics are strong and
pleasing *M ZX-S1). Grap

n ?0 — Thirty-two inverse t
30 — Space, inverse shifted M.
35 — Inverse space, inverse U
inverse space.

42 -Inverse space, graph"
graphic H, graphic C.
inverse space.

43 — Four inverse spaces,
!49 Inverse asterisk,

151 — Space*

152 — Inverse space.

412 — Five graphic Hs.

413 _ Five inverse spaces.

145

t*« ir

q;

1S2

ias

190

191

192

194

196

300

400

410

4-11

4J2

4-13

4.14.

4.30

430

4-37

4.3©

4.39

4.4-0

4*3

44-5

4.46

50

IP

IF

H,=ie then PRitrr

THEN PRINT RT H,G+©
THEN PftINT RT

tlT H=H t V^
IF F<Z-1 THEN

LET N=®

LET H^0
LET C=0
LET F=0

REM SCOPE

L l? HlTB=HlT|ta

FOR N=l TO 20 _

PRINT AT U,U, _

PRINT RT U,^

NEXT N 12 CHR* HIT3

^ I Kir^lt^'THfeN H GOT S00

LET FR-e

F gJ HS TO 30

NEXT N „

r|^=xTlST X ' ( RKD,3) + l

gglSr'.R? aU

32

© O

., . ..

1 ■ T

i*Sf*i§*B'

10 LET L=CGDE

^e LET R=CODE

30 LET B=R

4-0 LET M=ft

5© LET I=C ODE

50 PRINT

ftB L; "■»****** *P***i

70 FDR G~L TO CODE

3S PRINT J, B*H*^^*lt*$

90 HE XT G

100 PR INT "M* * *MitJt*3&** *$£ * 1 **" > 1
RB L,.

113 FOR F=CODE "■" TO L STEP -H

123 LET fi =& + f INKEV $ = " S " > - ( INKEY

13© LET &=&+ tINKE 1 i't = "8") - I XNKEY

14-© PRINT RT R^B; "C"

150 IF R-M RND B=I-H THEN PRINT
"SCOPE ";F,"ZX LIVES" ;U
16t3 PRINT RT l=i *B; " '■*

IT'S IF R=L OR R=CODE " : " OR B =L
OR 0=1 THEN PRINT "ZX-KILLED"; U
1S0 LET E=INT (RNDtCODE '{§" )
150 IF E=R RND B;R THEN PRINT ft
T R,B,; ,, B";TRB L:"GH05T GOTCHfl ,, ;U
200 NEXT F
210 PRINT 'TIME UP"

4

/

X-MAN is a silicon-based life

Z

form, writes its discoverer,
Chris Handley. It thrives on a
diet of asterisks but is killed
instantly by the inverse spaces
which make up its maze-like
ecosphere. Your task is to use keys
6, 7 and 6 to guide the ZX-Man
through the maze without running
out of time or into walls.

An additional hazard is provided
by the ghosts of previous ZX-Men
which materialise unpredictably
and gobble him up, Only in the home
straight is he safe from this ghoulish
threat-
It is an excellent IK game for the
ZX-B1, though the fit is so tight that
adding 's T to the word 'ghost' is
sufficient to halt the program.
Graphic notes:
60-17 Inverse spaces.
100-6 Inverse spaces, inverse 'ZX-
MAN\ five, inverse spaces.
180— Inverse E.
190 — Inverse G.

O

SINCLAIR USER Augustl982

33

1 51S ^SrxS^V-h™" "

»■=* E R

NF*

F

6
IONS

7

a
a

IB
12

IS
IS
17

19

ae

,10©
106

108

i i©
lis
110,

fiT

G"
J.©©

"DO

P*

*V"

11 ,*i

yOU URHT INSTRUCT

19B2
3 PRINT

R O

pause

PRINT

IHPUT
IF P*-

LET N=©

Let H=H
LET r-*

LET S»*

l|t g-g*

PRINT BT
PRINT i? T

13©

15©
4-0©

troggeh

tmCN l£ t

THEN

~ =3 *

PRINT RTfil^ A ^ TO 5©*

s?sVi. ».-•■» ■■" ,

./

i

^§i

Ai

^

jt

5U
515

. a

B S

a 1

5 39

5 5 Li
SSI
5S£
SS3
S55

PRXNT
PRINT

PRINT

«T
«T

or

1©,S; *

1* ,6 r ■"
1©,G; •■

8

■

PRINT at lej6 . ,._
IF C>| 3 THeN' L f r c

67 ^^L*B S*0 C

TH ^N LET 5=5-,

E-il'OPE

S63
I©

56<a

S75

B S o

160©

2000

2500

25ie

5S03 IP
3510

2504 I=r

o asia'

2505 t f

o asie
£5© e if

2S10
2507

r HE(.j

PRINT ft T £j

fg^%#>" BSB IIS

PRXWT of »i c iZ H x**£ty"

fOTTg 35flB ' i5; "SCORE

E^0
6"-: -0

E ! **
B ■: =0
E^=0
E-i =0

AND

ftftf)

^N£l

*;s

;s

•-1

E : =© j=J^i>

E i -0 «K&

W

o asif

■a mSrsFKii

C=R+£ THEN GOTO
C*»**a TM^N GOTO

c*»+a THeftr Goro
c^»*» THEH aoro
£«*»*** THEH Ctjtr

c ****s then eo T

«+£a THEN GOT

"SCORE - "

-5

34

SINCLAIR USER August 1SB2

Ti HIS VERSION of the arcade
game Frogger was autatted
by P Hammond of Ipswich. The
a is to lump the frog across a My

™e° Hhe moving frogCT r«rt-home 9

on the other aide.

Features include a running dis-
D J rf scores, instructions on
SinLat and a pleasing range ol

and frog-homes give Plop, Splat ana
Missed respectively-

Your frog is prodded into action

bonus for every frame it manages to
hesve itself across. Graphic notes.

10 7 — Inverse F>

510 _- Graphic 5. two graphic

As, graphic B.
512 — Inverse C.
5^9 — Inverse L,
551 _ Inverse F,
;~. ^r ~ -1 2521 — Inverse F.

50Q0 rp t= = I

5096 re c * HeM GOTO

s icia t f t _ * then e,i Tn

S400 F Fe3 *N£v C=fl +ia _ r °
5118 IF Ef^ 3 OMr , 1& f ^« GOTO

5 120 XF e-m „ f «^N 15DTO

54. B * E -l* «|.J & C-fl + j tup,.

Bl 3e IF • ,» THEJJ GOTO

SUA if -r.-- _ *^ T * E N GOTO

5150 f F E _ «--»*JS THEN GOT

POD3 ■ ""iL^.." 1 ^ «-.«: .nuM

9 g«3 PnrSr B £" *«*~ " T ™ lay
9 Sg^ P 5° M «g»^fSt::™^»««> ■ you

|i?g%C :; *••* — .«»„. c

Hit ?P L *^ "I5 CV " N ' L ""

&S 01 i F U ^>^0

S 1 ?^^ "£> D rot. i**^

9530 INPLIT v- GO ,,W *" F mother

9 54 STOP*' V ' T «EW GOTO tig

"^

ill! CgT*§«£***

IBS gtg.» ««> *-* THCH GOTO S

30^1 I* 5 e ~ lto H THCH GOTO

309 T _ __ l6 RHD C=l« THt "

3003 I F E - 1= * THEH SOTO

3*04 IP c tH fn GOTO

30CS IF c- THEM GOTO

3007 IF E^i THEN SOTO »

50^ TC - f-14- AND C-« THE**

3120 IF E- BM GOTO 5

31 £1 IF E 60TO

31£2 IF E-l* GOTO

3183 IP EM THEM GOTO

3 12* IF E-i THEN GOTO

3125 IF E-- ^ TH£H GOTO

3126 IP E ^ „-, THEN GOTO
||| 7 JF E=i* «nd e-«7

S ^« PRINT *T ^^ C i^3COPE " - -
i^i ^ 1T S^* , o + i THEN GOTO
S0 00 IF E THFH GOTO

5 ^^H X ! C -«*i« THEN GOTO

5020 IF E =* THEN GOTO

503© IF E ~ ^^, THEN GOTO

504(5 Jt= C ■=- THEM GOTO

5050 *F t THEN GOTO

| 06 IF £-«& rtHP t GX?T C

5 ^S IF E-6 PND C-**+i3 THE

5070 lr c

a\\

u .

£f^

f^x"

v.

5f/

//A

.-> >

•^i*'.*5?l"

^'V

:— i 5*3©

-<UJ£6£-

SINCLAIRUSEH Augysnafl2

35

TOWERS * HANOI

THIS game is from the
mysterious east via Simon
Annetts of Rhayader, Powys,
It is velly. velly good.

Your Sinclair will erect three
pegs and on the centre peg will place
six rings in order of descending size.
Your task is to transfer the rings one
by one until they are all assembled
in the correct order on one of the
other pegs.

You cannot place a bigger ring on
a smaller one and the computer will
chastise you if you try. An excellent
little game which went immediately
en to the office tape. Graphics notes;
30 — 32 graphic shifted 8s.
50 — Three spaces, graphic shifted
8, 7 spaces, graphic shifted 8, seven
spaces, graphic shifted 8.
67 — Three spaces, graphic shifted
8.

70 — Three spaces, inverse space,
graphic shifted 5.

80 — Two spaces, graphic shifted 8,
two inverse spaces.
90 — Two spaces, three inverse
spaces, graphic shifted 5.
100 — One space, graphic shifted 8,
Two inverse spaces,
110 — One space, five inverse
spaces, graphic shifted 5.
1 20 — Graphic shifted 8, six inverse
spaces.

10

iO

PRINT

TGUF-R^ OF HftMOI

RT &<3r . Q

35 PR INT RT 2 1 .. ©_. '
TRS 34.; "3"

J.0 FOR X=i© TO tar

BO PR INT RT X * 5 / "

1

NEXT X

1"..TR& it; "5e

60

65
67
7©
80
^Q

100

lie

IE©

133

135

140

145

1S0

155

16©

170

130

ir 1

190

1^5

201

£©5

DIM

DIN

LET

LET

LET

LET

LET

LET

LET

FOP

LET

LET

LET

NEXT

LET

FOR

FOP

R 13
ft * * 7 .*
R* *. LI
ft* '.Si
ft**.3>
ft* '4'
ft* *5>
ft* 16}
R* t7>
Z=T TO 1

R *3., Z? =2
ft 13*2.1 -1

Z=l TO 3
V=7 TQ t

STEP -1

STEP

PRINT RT V

♦ 13,2*8-3.. R* '■« tZ

NEXT V
NEXT X
PRINT RT
XF R f. 1 ., a
N GOTO 2808
SflS PRIMT RT

8.24, "HOME
=S OP. Rt3.»:

t=3

3 THE

216

330

240

350

2S5

THEN

260

270

2S0

3^0

300

3 10

3E0

330

34

350

360

365

3"70

3SO

400
410
420
1000
10 10
1020
1030
1040
1050

2000

LETED

0.

0;

TIVQH T"

PR INT ftT

INPUT *J

PRINT ftT 0^0; J;

INPUT K t ^

PRINT ftT Q.0.. **£~

if j s,3 or aa Of*

GOTO 100© ^.^

IF KsJ THEN GOTO

FOR D=l 7°. "?„_»,

T_F ft * J - O > s 1 THEN

LET P*D

LET = ft**l^t»

GOTO 340
NEXT D
GOTO 100©
FOR C>=i TO 7
IF 'fl(K,D)=l THEN
XF RtK.fr> <Q THEN
IF RtK\D>>t THEN
NEXT t>
LET Ds&~l
LET RlK.sOJ-RtJ.P'
LET R!J,P'f
LET G = G+1
GOTO 160
FOR U=0 TO
NEXT U
PRINT RT
FOP U^0 TO
NEXT, U
GOTO 306
PRINT RT ^ , ©,; "
THE TOU&P-5 OF

TO '

TO '
K. ; 3

1000

GOTO

;k

OR

H < 1

323

GOTO
GOTO
GOTO

37©

1000

360

= 1

3©

©.; " 1HURL II> HOUE '

v'QU HRL'E COHP
HRNOI IH"..C-

ij "MOUE5"
2010 PRINT

2020

2030

3040

RUN

2050

PRINT
INPUT

5*

ftORTN7'

IF S*^' v v'E:
5TOP

OP

* = "*Y" THEN

36

SINCLAtRUSER AufiuMJ9S2

INTEREST
VICUEATION

-** OES INTEREST interest you?
!f so, so will a program
mJ submitted by Christopher

>?n of Stratford-on-Avon. Enter
the amount, the percentage, the
length of time involved, and the
settlement period — the intervals at
which payments are due — and the

iputer will crunch until your
eyes scroll.

6 REM "INTEREST CfiLCULFfTION"
10 PRINT "ENTER THE ftMOUMT CON
CERNED"

21 PRlSf "ENTER THE PERCENTRGE

PER fiNHUH*'

50 INPUT B —

&Q PRINT "ENTER THE YEfiRS.. THE
N THE HONTHS"

70 INPUT C

S0 INPUT E

90 LET D=C#13«-E .

100 PRINT "ENTER THE SETTLEMENT

PERIOD IN MONTHS"

1 10 INPUT F

120 t_ET DD=D/-F

130 FOR Gsl TO INT D

1A0 LET H^INT <R* (BtF^lS* ) * 100

150 print "period *\; G.; " -. £*\: n; " +
" ; B ; "0^0=£".; fitH

1&0 LET R=R^H

1T0 IF PEEK 16U3C53 THEN 5CROL
L

1©0 NEXT G

190 PRINT "PRESS RNY KEY TO CON
TINUE"

300 IF INKE¥* = ,,W THEN GOTO 200

210 CLS

220 GOTO 10

SHUTTLE

LET

LET
LET
LET
FOR

& = URL
fri.sVRL
S=URL

F=WL
L=VftL

" 15'
"D t

"1" TO URL 1

RT * RND SVRL " 5 " !
RNDtl.'RL "20".V "•"
NEXT L

PRINT RT url "si*\.t;m,

12"
WRL

25

RT D j. F j

RT D,FfV

100 PRINT
RL "3" '

120 GOTO 200**200 RND tPEEK iPE
EK < ISSQE* +S5&tPEEK * 1653^) * > =6l
+ 1200 RND FafiBUtaW RND F (65 RN
D D=21)f (48© RND F=&5 RND D=3i>

200 print rt &..f.; "

E01 LETT DsO+aNKEV>< ,■■"?") -(INKE

2S5 LETT F=F^RL "1" __ = =

IF IHKEV*="7" THEN LET S-S*

1"

GOTO URL " 100" _

PRINT RT D,F,"«5*".'E _, v ^ v

PR INT RT K » K ," "VQU UIN FUEL

210

URL <

230

4.03

1000

USED-"; 5

PROJECT yourself to the heart
of the Nevada desert as you
steer "the heaviest glider in
the world' to a safe landing.

It is a Land the Space Shuttle
game, submitted by G Banks, of
Wakefield, West Yorkshire.

The display features the shuttle
drifting down diagonally from left to
right, through a number of obstacles,
low-flying vultures or loosened
thermal tiles, perhaps. A stab on the
7 key will boost the shuttle tempor-
arily to a higher altitude while still
keeping it on line, you hope, for the
landing pad on the right of the
screen.

The game is suitable for an un-
expended ZX-81. though you will
find yourself running out of memory
periodically and in rieed of the
CONT button, Graphic notes:
60 — Graphic A.
80 — Three graphic Ds.
100 — Graphic W h Graphic 6,

Inverse space, graphic W.
400 — Asterisk, inverse asterisk,

asterisk.

;t:fl AuKu<*tiW2

37

THERE WAS A young fellow
from Lanes,.
Who sent us a program which

ranks
As the beBt of all time
For churning out rhyme
And it hereby is printed with

thanks.
The basics of an excellent
program. Your own ingenuity — or
genius — is the limit.

Submitted by Jonathan Finstem of
Salford Lancashire. (16K ZX-Bl)

LIMERICK WRITER

A REM "PU"

5 CL.S

6 1_ET ft=0

7 LET B=&

8 LET ft=fi+l

9 IF A =6 THEN GOTO 2O0

10 LET fl»='THERE 1>RS R YOUNG H
t=1N FROM "

ae lett b*--uho

30 LET D*="HI5 "

4.0 LET D>-"ONE MIGHT ftFTER DRR
K "

SB LET E*-"HND HE NEWER UGRKED

OUT "

55 LET 6=B + 1

&© LET N=INTT IRND*4)+1

70 IF R = l THEN PRINT .R*J

71 IF Btl AND N = l THEN PRINT J

Tfi
SHKENT"

72 IF 6 = 1 RND N = 2 THEN PRINT ;
"TRENT"

73 IF B = l RND N -3 THEN PRINT ;
KENT ■*

7* IF B=l RND N=4. THEN PRINT ;
GHENT"

77 IF R=2 THEN PRINT :B%:

76 IF 6 = 2 RND N = l THEN PRINT .

"URfiPPED UP ":

79 IF B = 2 RND N=3 THEN PRINT ^
"COUERED ":

50 IF B=S RND N-3 THEN PRINT ;
■ i pi f^ j; ^j ED " " i

51 IF 6 = 3 RND N=4 THEN PRINT ;
"FASTENED " ,

82 IF H=3 THEN PRINT :C*,

33 IF Bz3 RND N = I THEN PRINT ;
" HERD " ;

64 IF 6=3 RND N=2 THEN PRINT J
HAND "j.

53 IF B=3 RND N=S THEN PRINT :
DOG "J

8© IF Bs3 RND N=4 THEN PRINT ;
1 FOOT " :

67 IF 6=3 THEN LET BiB+i

86 IF 6=4 RND N = l THEN PRINT ;
"IN R TENT"

69 IF B=4. RND N=S THEN PRINT ;

UITH CEHE
NT"

90 IF 6 = 4. RND N =4- THEN PRINT ,

THRT
URS BENT"

100 IF 8 = 4. RND N=3 THEN PRINT ;

UITH S
QME 5CENT"

130 IF fl=4 THEN PRINT ; D*

13© IF 6=5 RND H-l THEN PRINT ;
IT RAN OFF ";

131 IF B=B RND N=2 THEN PRINT ;
IT GLOWED " ,

132 IF B=5 RND N=3 THEN PRINT .;
'IT BLEU UP ":

133 IF 6=5 RND N=4 THEN PRINT .,
" IT TURNED BLUE " \

14© IF B^5 THEN LET B=B+1

14.1 IF 6=6 RND N = l THEN PRINT 1
■ IN THE PARK "

14-S IF B = B RND NiS THEN PRINT

LIKE R QUARK "

14-S IF Bt=6 RND N = 3 THEN PRINT .;
'FOR R LARK"

14-7 IF B=^6 RND N=4. THEN PRINT j

UITH R BRRK""-

1B8 IF R«5 THEN PRINT :E£:

170 IF B-7 RND N-VTHEN PRINT

WHERE
IT WENT*"

171 IF B=7 RND N=2 THFN PRINT i

IT
8 INTENT -

172 IF B = 7 RND N-3 THEN PRINT .:

UHV

IT UENT"

lf73 IF 6=7 RND N =4. THEN PRINT .i

UHRT
IT HEflNT"

190 GOTO B

2GB PRINT

205 PRINT "COPY? (Y OR N)"

£10 INPUT U*

215 IF U*«"Y" THEN COPY

220 PRINT i "DO YOU UANT RNOTHER
7 CY OR N) "

230 INPUT 2|

250 IF Z£=-Y " THEN GOTO 6

300 STOP

3 10 SAVE "PU"

320 RUN! 5

38

SINCLAIR USER August

interface
review

*
I

Stephen Adams looks at the Data-Assette
ZX-99 and finds it good but that it could
involve a lot of expense.

Control system

inn

>sts power

THE ZX-99 is a control system
for up to four different tape
recorders which also has an
RS232 tape interface for running a
printer. The tape commands are all
stored in a 2K ROM between 6K and
10K but the total area used is the
whole of the 8K section between BK
and 16K. That is because of the way
the ZX-99 divides the tape recorders
— there must be at least two to mate
a sensible system — into INPUT and
OUTPUT tape recorders. The two
input sockets are selected in-
dividually and one lead is provided
with the ZX-99 to connect the EAR
and REMOTE sockets on the tape
recorder. The normal cassette leads
are plugged from the ZX-fll into the
ZX-99 at the top and all of the
SAVEing and LOADing is done
through the ZX-99.

There is a 50-page manual with
the ZX-99 and it is well worth
reading before starting. It is well-
written and contains not only a

chapter on all of the commands but
example programs, problems which
may occur and any peculiarities of
the system.

The commands are in the form of
USR calls to various parts of the 2K
ROM which can either be used
direct from the keyboard or within a
program, It is very easy to use in

which string is used for the buffer —
i.e., Z$ = "X" — and variahle Z the
length of thet buffer string to be
sent. The Y variable is used to
control the printing operations of
the RS232 interface.

The variables can be pul to other
uses in the program but must be
filled with the correct data for the
ZX-99 before doing a USR command,
or an error code will stop the
program* There is also a "com-
pletion code' h in the form of an error
report when LET L = USR 1234 is
used. Variable L can be checked if
there has been a fault, as the report
will be if all is well.

One of the useful extras provided
by the code is a check of the quality
of a program which has been read
back from the tape by the ZX-99. It
consists of checking for three com-
mon errors — too high a level, too
low a level, and varying tape speed
giving longer pulses thao are to be
expected. A number which gives the
sum of the three errors is returned
in the completion code if they are
found. The USR commands provide
the following functions:

• Turn on the tape drive of any
one input or turn on either or both
of the tape drive outputs,

• Read or write a data buffer of
length Z into or out of the tape
recorder. On output, two copies
can be made if required, one from
each output.

• Skip the next block of data or
program on tape.

■ LOAD a program into the
ZX-fll memory from an input tape

'One of the useful extras provided by the
code is a check of the quality of a program
which has been read back from the tape.'

Basic but it requires the use of
several variables to be set up for use
by the ZX-99 before the USR
commands are used.

These are a single-dimensioned
string (DIMX$(300)), Z$, Z and Y.
The dimensioned string can be any
single letter and is used to store the
data to be sent or received from the
tape. Z$ is used to tell the ZX-99

drive and then SAVE it again on to
one or more output tape
recorders.

Print-out a data buffer to an
RS232 printer. Y defines speed,
number of stop bits, parity and a
choice of upper- or lower-case
printing of the Sinclair character
set. All codes sent to the printer
continued OH {nige 40

SINCLAIR USER August 1982

39

V *

continued /rom page 39

are in ASCII and the user can
define any ASCII character.
• Print a full list of a Basic
program to the RS232 printer. No
controls are provided — only the
data and the common. Graphic
characters are printed as ASCII
codes.

TheRS232canbeusedonlywitha
printer, as only an output on 3.5mm.
jeck is provided. All the ASCII
control and other codes, including
upper- and lower-case, can be
generated from the keyboard or
from within a program. When using
a data buffer to printout a string of
characters, carriage return and
line Feed are separate but <> will
produce both for a new line.

The length of the printed list is
limited only by the maximum length
the printer can print, so long lines
will look completely different on the
printer. The speed at which the
printer can work can be between
1 10 and 9,600 baud but the RS232
port expects to print at full speed, so
the printing speed must be adjusted
to that with which the printer can
cope.

The graphics characters in a
ZX-81 program are all converted
into ASCII characters and are
printed as such. That means that as
some of the graphics correspond to
control characters it could cause
some weird effects on the printer,
such as double-sided characters
and graphics dots. The only way to
avoid that is to convert all the
graphics into CHR$(x] but that
wastes memory.

On the latest models, when
LISTing the program, the graphics

characters have been converted to
spaces, enabling the user to fill-in
the gaps with the appropriate
graphic when the printing had been
completed.

The original ZX-99s did not do
that, causing problems in the
LISTing. Data-Assette has offered a
new ROM to people who bought the
original model.

That does not apply when printing
a data buffer, of course, as CR/LF
can he done at any time along the

'Non-restoration of

slow mode on

return to Basic is

also annoying/

entire length of the printer. One
useful thing in the LIST rootine is
that it generates a blank line after
single GOTOs. GOSUBs or
RETURNS, showing the end of a
routine.

The tape LOADing and SAVEing
are done at the same speed and in
the same way, using Sinclair ROM
routines, so there is no increase in
speed. The fact that five seconds of
blank tape is recorded between
each piece of data also means that is
better only to SAVE to tape large
amounts of data, otherwise the data
records take so long to load.

CLS is also recommended to be
used during data recording, other-
wise that causes noise in the silent
part of the tape. A data limit of 40
bytes is also imposed on the user as

the minimum the system will put on
to tape.

Block skip will check and report
tape errors but will not verify the
data against the program in
memory, COPYing a program over-
writes all the system variables, so a
re-start is made after one program
has been copied, thus NEWing any
program in memory. BREAK is
recognised throughout all the
routines and will revert to a Basic
listing as normal, except on COPY,

The ZX-99 has some very good
features to build into programs
where data needs to be written to
and read from a cassette tape.
Unfortunately that does not improve
the speed of transfer, as the same
tape system is used. The minimum
requirement is two tape recorders
at once, which may prove a strain on
some budgets, as well as the cost of
the ZX-99, which is £62.90 including
VAT and postage.

The printer routines included are
very useful for doing reports and
graphics on a real paper printer, as
the printer is under complete user
control. The differences in ap-
pearance, such as the represen-
tation of lower-case by inverse
letters on the screen and the limit of
32 characters per line on the ZX-61.
would have to be solved by the
program.

The non-restoration of slow mode
on return to Basic is also annoying,
as the ZX-99 works only in fast
mode, for obvious timing reasons.

In all. a very good tape control
and printer system. The ZX-99 can
be bought by contacting Data-
Assette at 44 Shroton Street.
London NWl 6UG. 01-258-0409.

40

SlNCL A IR U SER A ugust 1 WZ

KEMPSTON MICRO ELECTRONICS

SSST zx KLIK - KEYBOARD

IF YOU AR E (ike manv ZX81 users and are fed up with the
dead "touch sensitive' key pad then consider the advan-
tages of the new KEMPSTON KLIK-KEYBOARD. This is
a genuine push button keyboard which has been
designed as an exact replacement, being no larger than
the existing key pad, but offering all the advantages of a
full size keyboard. Consider these facts:

• FitsontotheZXSl.
•No soldering needed on the assembled version

(just plug in)

• No trailing wires -
•No special case required.

• Positive feedback from keys.
•Full two colour legends supplied.
•Full back-up service offered, including fitting.
This is a genuine 40- key , push button keyboard which fits
into the recess formed after peeling off the existing touch
sensitive keypad.

The kit comes with a precision drilled P.CB. finished in
matt black, 40 keys. 2 colour legends, connecting tails,
adhesive pads and a full set of instructions.
STOP PRESS STOP PRESS. . STOP PRESS
NgwSinctair Spectrum H/ W 24 line input output
Port has now been developed, allowing access to
the outside world. Using a single in or out instruc-
tion - SA.E. for further info.
Also available from our range of products is a
Parallel User I/O post £16.50 built £r tested. Gives
161/0 lines to drive light relays, motors etc. Many
already sold to education. Keyboard bleeper £8.95
built.

<M ■«"• K4 *>»*■« .

DH

ftWI^ O^nrp'rh

!*<*■

lIlllMllll

/XHl ».,l,.i».<! Fi-

OR

50

ZXil KnfeMid AaUrnbM

n

■

hanw

*tij*f iHiw H ,!■■■ Iv Mttvrfc

70

IWHHR

Proprietor A. Pandas!, fi.Sc, P.C, Cert. Ed

What is the best way to guarantee that you
never become bored with your Sinclair
computer?

The answer is to subscribe to Sinclair User,
written specifically for owners of ZX-SOs,
ZX-81s and Spectrums. Sinclair User is the
latest montly from ECC Publications —
pioneers of Practical Computing, WHICH
COMPUTER?, and Computer & Video
Games. Whether you bought your system
yesterday or are an old hand, you are probably
an enthusiast for your machine ad your biggest
problem is likely to be obtaining all the
information to satisfy your interest. Sinclair
User is devoted to quenching your thirst for
information,

As the name suggests, the content is geared
specifically to helping you t the user. There are
pages of information on available hardware
and software. Our aim is to make Sinclair
User invaluable and we chronicle applications
which are of special interest.

Make sure you
get it each month

Can you continue to obtain the most from
your Sinclair without reading Sinclair User
every month? So why not fill the subscription
order form today? Send it to Sinclair User,
ECC Publications, 30-31 Islington Green,
London Nl 8BJ.

Overseas imti Euiop* £ 1 8 . Oulsid* Eur op* £24 (Including air-mall pusugi I Chequin ihuuld
btf made payable to EEC Publiulioni

Subscription Order Form

[ wish to start a subscription to Sinclair User. I

understand that I may cancel my subscription at any time

and you will refund the balance.

□ I enclose a cheque for £9 for 12 issues (U.K. only —
including postage) .

Q Please charge my credit card.

Card Name

Address

No.

Signed.
Date

SINCLAIRUSER August 1982

41

HILDERBAY LTD

Professional Software

SPECTRUM

SOFTWARE

now available!

Details from us.
48K Payroll £25 until 21 September

Tape recorder suitable for microcomputer use,
aligned and tested on computer signals £22 + £2p&p.

Hiderbay Loading Aid. Load your microcomputer
from tape first time every time! £5.96.

ZX 81 16K RAM packs, comprehensively tested
(for bad bits, addressing faults, printer saving}
£30,

HILDERBA Y SUMMER
ZX-81 SALE

Beamscan (beam analysis)

Payroll

Stock Control

Optima*

Budget I & II

Time Ledger
Critical Path

Financial Pack I
Gold

£13 each

£20 until 21 September
£9 (2 programs!

£8 each
£5 each

These programs have been described and reviewed
previously lor we can prove details).

AM prices include VAT, and are post free. Sale prices are valid
until 21 September 1982. Free updates, comprehensive
telephone and personal support, and competition prizes are
not available for summer sale purchases.

HILDERBAY LTD

Professional Software

8/10 Parkway

Regents Park

London NW1 7AA

LTEXT AND ZTEXT
ZXSi WORD PROCESSORS

lower case characters
on the ZX printer!!

£7-50

No longer need you be confined Id space ggnw. botltethip* and it* we With ihrsr
programs your 7YJII ixttextih * viable cnmmaKiH machine. ZTEXT (uptmr cas*
characters only i and L TEXT (upper and lower case chancier*! *r<t word iHwrnwi which
incorporate 3 lent editor and » Formetto* /prinrrr Ths rem Bdiitir allrnnisvuu <» iyp« i*«] m
and edh it The rnmuiiwti/pnriwi takea Hie tear and sends n 10 be icreen of ZX primer,
|usrilvi'»B 1 1 and tormadmg accordingi Id commend* embedded in lha test Inr ludmJ in ir.c
range M commands nrp tueh uwlul rmmtinns a* string search, tiling replacement and a
mprgfi Pnciliiy t'riutiliny a iKulerun document 1o be filled wiih wxiblei irtfcimvalicn L TEXT
caiersfor bolh upper and lower casechenKtn. No. Ihai ■» ncn 4 mr*prmi Bv MMl| the
nigh resolution prvhvi 1«aiurc at iha £X pr" mier Graham Asher l>« cuilt a CDrnpJew hi of
lower cas* characters. These urogram come comrjlele with ■ detailed manual

5c™i 9Sp imtmemdbit; again*! tirsr tx dar I For lull catalogue

and FBEE hsi-ng Please -siaie Z*8 1 on order

All prices include VAT and PErP available from

□BiisSolTwara. Lower North Street. Cheddar. Somertet

Tel: Cheddar 743*09

Dealer enquiries welcome

iccessqbD'EPis,
t*kem bv phone

MHQLWS * D*T

Tel: 01-485 1059

TV/**: 22870

ZX CHESS & ADVENTURES

PROGRAMS FOR THE ZXB1.'HD INClUPINfi

MOVING AHEAD

WITH

ZX SOFTWARE

^ftE$ ZX- FORTH

16K RAM PACKS
^£29.50

IK ZX-CHESSff
£2.95

ZX CHESS I
reduced to £6.50

ZX CHESS II
now only £9.95

ADVENTURES
ADVENTURE 'A J

E6.00
ADVENTURE 'EV

E7.00
ADVENTURE 'C

E8.00

GALAXIANS
£3.95

ZXBUG
£7.00

and many more. For

Full implementation of FORTH for the ZX - 10 - 20

time faster than BASIC 'Sm-ieticity of BASIC wflh

speed & machine code.'

BYGBYTE RAM PACKS, no wohhtepraWaiTiS. 1 ySftT

guarantee on eacti RAM PACK The best you can buy.

Immediate delivery.

We didn't ihink ii was. pussible, but (he game plays

against you, two opening moves, only IK of nfarfioty

needed.

Very popular machine code program, with sin levels of

ptay and an analysis, nplton. Unbeaten except by:

A now intpfoved version lAiiltv a taster response lime,

seven levels of play, and in adrtlion a recommended

move option.

Exciting machine code games wiih trwtant H Mp o m tj

choos* from itw rgnge below. You find yourself

siranded on an alien ptanst.

Can you reach your ship and escape;"
In a itingle clearing you corns acrost an tnca temple
You must break in, collect lreasure and escape aRv*.
Beware Includes a cassette save rouiinE.
Yqu. ere urlfortunatfi enough fo be drawn tcj an alien
cruiser. Can you reach the contra) foom and Tree
yourself or will they get you first?

Includes a cassette- save routine
All the features of the acafde game in a fast machine
code program. Swooping attackers, explosions and
personalised scaring.
A 30 in 1 machine code tod and dilMle m totar, gUowi

access to all registefs and to search through, and

modify memory; with cassette rooiiriBS.
a catalogue giving fuH d&tafe, please send a SA.E In

Artie Computing

Dept EE

396 James Reckirt Avenue

HullHUSOJA

4Z

SINCLAIR USER A ugus 1 1 W2

hardware
world

'"vC

K

Little switch
into reverse

THE ZX-81 video invertor
consists of one integrated
circuit, which is an npn
transistor array, seven
resistors and one coupling
capacitor, all contained on
one small PCB — 20mm. by
32mm. — which probably
is manufactured using a
Photolac process. The idea
behind the device is to
reverse the conventional
display to give white
characters on a black
background, a switch be-
ing provided to return to
normal display mode.

The PCB is held in place
by a strip of double-sided
adhesive tape on top of the
logic chip ICl, although
that is only for location
purposes. The device
works by intercepting the
signal to the modulator
and installation requires
the cutting of a wire to the
modulator and soldering
four wires in appropriate
positions.

The toggle switch is fit-
ted to the rear of the ZX-81
case and a '/« in. hole has to
be drilled to accommodate
it. Many Sinclair users
may be justifiably reluc-
tant to drill holes in their
ZX-81 s so it may be possi-
ble to locate the switch in s
different way. or perhaps
omit it completely and stay
in inverse video mode.

The invertor costs £3.50
and is available from
Dieter Fritsch. G5CKZ, 6
Stanton Road, ThelwalL
Warrington, Cheshire
WA4 2HS.

A similar device is
available from B A Reader
to the one just described
but consists of a single IC

and a rather over-sized
toggle switch, both being
mounted on a small piece
of Veroboard. The manu-
facturer has indicated
that a smaller switch is
now supplied with the kits.
Installation again consists
of drilling a hole located on
top of the ZX-81 case —
although space im-
mediately below the
switch is very limited —
and cutting a lead to the
modulator.

This inverse video
switch costs £3.75 built
and £2,95 as a kit and is ob-
tainable from B A Reader,
45 Alfred St. Kings Heath,
Birmingham B14 7HG.

be used to display any-
thing which fits on the
column x 7 format. The
displays are available as a
kit — LED boards made up
— or ready-made for
between £62.01 and
£356.50. including VAT T
interface and program to
run it, Contact ADH
Systems Ltd, 209 Mackie
Avenue, Brighton BNl
8SE. 0273-557429,

Fulcrum
bleep

socket.

The device works in
both FAST and SLOW
modes although it does not
function on certain shifted
keys.

Since the review was
done the company has
brought out the ZX-81
Keyboard Bleeper which
covers all 210 characters.

The ZX-B1 Bleep and the
ZX-81 Keyboard Bleeper
are both priced at £8.95.
including VAT and
postage, and can be
obtained from Fulcrum
Prodocls.

THE Fulcrum ZX-81 Bleep
consists of a small PCB
measuring 3±in. by 2in.
which fits into the space
inside the ZX-81 case,
underneath the keyboard,
That particular space is
much favoured by other
manufacturers for their
add-ons, so it could be

Colourscreen
for tired eyes

ELLANBEE [Graphics] can
provide a cure for tired
eyes from too much staring
at a bright TV screen.
Colourscreen is a large.

•*• •**

♦J" ••

*«■ •*••

ADH display interlace

Display
interface

ADH SYSTEMS has prc-
dced an interface which
allows a ZX-81 to control a
LED or filament lamp
display for advertising in a
shop window. The system
can control a IS, 24. 40 or
80-column display and is
n o I li mi ted on) y to numbe rs
or figures. The display is
seven LEDs high and can

difficult to fit any other
device there since the heat
sink is close to it.

The sound, which is a
short bleep, is made by a
small transducer which is
located in one corner of
the PCB, Fulcrum empha-
sises that Ihe device
requires no soldering, the
connections to the ZX-81
being two wires for power
and a 5-way flexible cable
which plugs inlo Ihe
existing keyboard tail

coloured, optically-clear
plastic sheet which goes
over the TV screen. It is a
15 x 12in. sheet which is
cut to fi I the size of von r TV
screen and then fitted
carefully over il.

II requires no tape or
other fixing and can be
removed al any time. It is
in two colours, blue or
green, with instructions
and a specie Uy-stiffened
storage envelope, a< h cost
continued fin page 44.

SINCLAIRUSER AljhusI 1982

43

continued /rom page 43.
of £2.95. Larger sizes are
available on request from
Ellanbee (Graphics], 11
Lichfield Close, Great
Lumley, Che ster-le-S tree t,
Co. Durham DH3 4QH.
0385-886967.

also selling a book on com-
puter graphics at £1.50.
All prices are inclusive of
VAT and paper can be ob-
tained from various ZX
computer shops.

New supply of
printer paper

PRINT-N-PLDT Products,
which produces a display
mapping book and foils, is
now supplying printer
paper for the Sinclair
printer. Silicon Tricks is
not now supplying paper,
so this would seem the only
alternative to Sinclair.

The quality is as good
as. if not better, than that
of Sinclair and at E 10.95 is
cheaper, Print-N-Plot is

Memory
chunks

EAST LONDON Robotics
has produced a incremen-
tal RAM board which
allows you to add up to 16K
of static RAM in 2K por-
tions to a ZX-8 1 . The board
fits inside the ZX-81 and
can be used with any RAM
pack available. It requires
no soldering to fit the
board and its instructions
cover nearly every
possibility.

The board uses 6616
static RAMs and cao be

ZX81

the BEST yet
from MX. Associates

44

PELOPONNESIAIM WARE

— a brand new 16K game
Your ultimate goal is a final victory over the Spartans but
you will need to deploy all your skill in a combination of
diplomacy and military force before you even stand a
chance!

Price £5.95

also

TYRANT OF ATHENS Price £4.95

ROMAN EMPIRE Price £5.95

Buy more than one cassette and deduct SOp from the

price of each.

Cheques or POs please - made payable to:

M,C. ASSOCIATES

4 GRANBY ROAD, CHEADLE HULME

CHESHIRE SK8 6LS

addressed into any posi-
tion in the memory map.
The BK incremental board
costs £12.01 and the 16K
£1 3.23. To that must be ad-
ded the price of the RAM
chips at £4.93 and 45
pence for postage if the
order is less than £15. East
London Robotics is at
Finlandia House, 14
Darwell Close. East Ham,
London E6 4BT,

Remote
controller

STRIPELAND LTD has
produced a computer in-
terface for the ZX-81
which can control another
device in another room
without wires between the
two. The mains wiring is
used to transfer a signal

from lha micro to the
remote control unit a Hack-
ed to an other device.

At the moment the com-
puter can only send
signals and not receive
them via the system but
modifications to produce a
two-way device will be
available soon.

The ZX-81 computer in-
terface costs E61.40 and
the remote control £27.50.
inc. VAT and postage,
Stripeland is at 111 Liver-
pool Road. Formby.
Merseyside L37 6BR H
0704-878062.

IN the June edition we
published the telephone
number of Eprom
Services, 3 Wedgewood
Drive, Leeds as

0532-667 IBB. This should
have been 0532-667183.

ZX81 16K

LOTHLORIEN

COMPUTER GAMES

New release "Warlord" £4.95
A16K game set in 13th Century Japan

• Can you rule a warring village to survive for 30 years?

• Can you defeat the armies and samurai of other
warlords?

• A challenging game where all results are dictated by
your own decision.

"SAMURAI WARRIOR"

Could you survive in 1 3th century Japan?

• In combat with other Samurai
■ Fighting bandit groups

• Assisting villages

or will you commit ritual suicide?

Become engrossed in this game of skill

for only £5.95

Cheques or POs please, payable in:

LOTHLORIEN COMPUTER GAMES

94 Flixton Road, Urmston,

Manchester M31 34D

SINCLAIHUSER AukusI 19t

mind
games

PMARSON, from Mensfield,
Nottinghamshire has what look
like two good programs,
HexaPawn and QuadraPawn. He
has included 10 pages of details
about them but I have not had time to
read them,

It makes a change, though, to see
that amount of documentation; most
people supply very few details. He
asks a question about how much
memory a program takes but I feel
that it would be more useful for him
to know how much memory is left, as
he will then know how much free
space he has. taking account of
variables as well.

He will also know how much his
program is taking up, variables and

Philip Joy looks into his postbag and finds
a wide variety of competition entries, new
forms of chess and anagram games.

Good response
to Nim contest

structions look like this;

Print USRx,
What I want to know is x. its decimal
value; the first person whose letter I
open will be sent a copy of my adven-
ture program. Please mark the letter
USR competition.

I was delighted to receive a
number of versions cf both one- and
three-pile Nim. I have decided to
give copies of my adventure game to
J Leaver, Bedford College, London;

all. by taking away that figure from M Woodruff, Accrington, Lanes. H

his memory size. I know of a USR Duncan, Cambridge; J Williamson,

routine in the ROM which will give West Lothian; I Slracey, Ely. Cambs.

the amount of free memory. The in- If they will send me a SAE with at

i

"mimv.ho.OF HATCHES VOL! MHY TWE <

4

I. Li

15
£0
25
39
35
46
43

55
69

65

'YOUR
"NO.

GO"

Or WATCHES LEFT=";X.

''VOL

LET ,:>VRL "56*
PRINT '»NIir;Tfl8
PAUSE 123
CLS

PRINT AT 0,9

PRINT f\l li..

INPUT fl

IF f\>3 OP fl<l THEM GOTO £€

LET X=fr-fl

PRINT RT 11,5: "MO

IF X=0 THEN PRINT

PRl^T AT 0,0- " rf

LET D-X

GHSUB 160

IF 0*X THEN LET X*X-INT<RN0 * 3M

PflUSE 120

IF X=9 THEN PRINT AT 0,8
GOTO IfJ
FOR H=9 TO
IF X-i=4*H
X-2-4*H
■ : :->4*H
T K

n ii

OF MBTCHES
BT 0,0
GO 11

LEFT=";X;
WIN",Q

WIN

Q

i j
100

103

ne

115
126

IF
IF

NE.'

12

THEM
THEN
THEN

LET
LET

LE T

x«x-x

r erTUp>l

least a C20, 1 will copy the adven-
ture on to it for them.

If you send a tape to me and would
like it returned, please enclose a
SAE,

Some of the versions of Nim fit in-
to IK and one is listed, while others
use machine code or show very high
skill. So people have won a copy of
my adventure for different reasons.
The version listed is a winner, from
Hugo Duncan, of Cambridge; it fits
into IK of memory.

Duncan says that the number of
matches may be changed by chang-
ing line landlinelOO.Hesaysthatif
it is changed to a multiple of four,
the ZX-81 is unbeatable.

Returning to chess, t thank Mr
Egdoll of Glasgow for sending some
more matches. I will be including
those games hut they take a long
time to check and comment on ready
for publishing.

I received a letter from the Elec-
tric Pencil Co of North Humberside
about chess programs in general I
was asked to compare Chess 1-ZX
chess — to the Sargon chess pro-
gram and Chess II lo the TRS-80/VG
Sargon 2,5 program. I have a Video
Genie computer and a copy of the
Sargon 2.5 program and I can say
that if Chess II plays as well, it must
be very powerful.

Two programs were received this
month which are different from
what has been included so far. They
are Anagram and Crossword but
were received too late for review
this month . At first glance it looks as
if they are good.

The address to send answers to
problems, or about any other idea, is
Philip Joy, 130 Rush Green Road.
Romford. Essex. RM7 OQA,

SINCLAIR USER Ausus* i BB2

45

BBC

t«*2£

*!OlH

MAKE THE MOST OF YOUR MICROCOMPUTER WITH
OUR POPULAR RANGE OF PROVEN BOOKS:—

GETTING ACQUAINTED WITH YOUR ZXS1 , by Tim Harmell. Eighty
plus prog ra ms m 1 his 1 28- page book, including dra ug his. E 5 . 95

20 SIMPLE ELECTRONIC PROJECTS FOR THE ZJC61 and othsr
computers by Stephen Adams £6,45

MASTERING MACHINE CODE ON YOUR ZXB1 OH ZXBO, by Tort

Hisksr tSO payes, leaches machine code Irom lirst principles

E7-SO

49 EXPLOSIVE GAMES FOR THE 2KS1, edited by Tim HartneU

E5-95

34 AMAZING GAMES FOR THE 1 K 2XS1 by Ala stair Gourlay

£495

THE GATEWAY GUIDE TO THE ZXfll AND ZXBO. hy Mark

CfiarlSDn.Ovtir 60 jirograma and routines, Z* BASIC explained m

detail £6.45

D LEARN PASCAL ON ZX81 ZK SPECTRUM OR BBC MICRO-
COMPUTER WITH PASCAL FOR HUMAN BEINGS', by Jeremy
Ruston, wh ich conla ins a 1 2 K co rnpjler so you can run a I im ited version
of Pascal on ycujrZXSI, ZX Spectrum or BBC Mtcrocompuler Book,
pJus compiler lislmg £4.95

LET YOUR BBC MICRO TEACH YOU TO PROGRAM, by Tim

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' THE BBC MICRO REVEALED, by Jeremy Ruston The lull story on
the BBC Micrrjcompuierfar the serious user. £9.95

GETTING ACQUAINTED WITH YOUR VIC 20. by Tim HartneU with
over 60 programs to get your VIC up and running from day one.

£0.05

SYMPHONY FOR A MELANCHOLY COMPUTER by Tim Haflnell

2* great V»c games. GS.95

39 TESTE D PROG P AMS FOR TH E AC OH N ATOM Best of I nlerf ace

edited by Tim Hadnell £6.45

□ GETTING ACQUAINTED WITH YOUR ACORN ATOM, by Trevor
Sharpies and Tim H-grtneii. 184 pages. SO programs, including
draughts £7.95

INTERFACE, the monthly magazine published by the NATIONAL
2X USERS' CLUB is |ust E9.50|U.K.Jl El 2 50 (Europe) lor 12 issues.
Sample copy, iwitn many programs for your ZX computer, booh,
software and hardware reviews, education, conlact addresses.
just n

■AttlW 000*3 irotr conrtifi Sptcltufn suppJomnrr. rtor avwrabrr nrpBrmmty
Ail Our ZXB I prou-'dn i mil run on f&* IX SDMlrom

Please send me I he items marked. I enclose C

Name

Address

Please make cheques payable to INTERFACE and send the above form,
or s pnpy. to INTERFACE. Derrt. 5C . 44-46 Eeris Court Road,
London YVB 6EJ
> allow up to SfltHrys tor dolrvwy.

HAVEN HARDWARE

Ttio World's largos 1 range of ZX Htrdwars
PROGRAMMABLE

CHARACTER GENERATOR KIT £17 95 BUILT £24.96

The FIRST end Still the BEST NO MOTHERBOARD or EDGE
CONNECTOR required. Works DIRECTLY with ZX PRINTER and 16K
MEMORY HIGH RES Graphplotter etc included

FULL SIZE KEYBOARD with REPEAT KEY b SINGLE KEY

RUBOUTetc

Specially designed for the ZX80 and ZX.81 . Still the only keyboard with

all these features. KIT £18,46 BUILT £21 .95

(REPEAT KEY £1.45 extra, SINGLE KEY RUBOUT Ef CURSOR

CONTROLS fl .45 e*tta,

REPEATING KEY MODULE KIT £3.50 BUILT f 4 95

UPGRADE YOUR ZX FULL SIZE K EYBOARD TO OUR STANDARD Of
use this module with the standard keyboard.

SEE SINCLAIR USt R MA Y 1SB2
•" TENS OF THOUSANDS OFSMCLAIR COMPUTERS
A LREA OYHAVE THtS FACILITY ***
INVERSE VIDEO MODULE (ZX811 BUILT £5 96

Thousands of Sinclair Owners have already seen how much clearer
their display is in white on black. WHY NOT JOIN THEM?

ZX8QCOL0URBQARD KIT £39.96 BUILT £49,96

ANOTHER UNIQUE PRODUCT.

Define the colour of each character square from a choice of sixteen,

Position on P.C.B. for mini-motherboard.

ZX EDGE CONNECTOR (GOLD PLATED) £2.29

ZX I/O PORT Interface your

computer to the real wo 1 1 > I KIT £9 , 96 B U I LT £12.96

ZX 3K MEMORY EXPANSION

Uses reliable STATIC RAM KIT £11. 96 BUILT £13.96

THE CHEAPEST SMALL MEMORY EXPANSION AVAILABLE

ANYWHERE-

ZX SPECTRUM EDGE CONNECTOR £2.95

ZX SOLITAIRE CASSETTE All cassettes are tested before
dispatch £4,96

OTHER PRODUCTS: Mottiertward, Numeric Keypad, Sleeper. Single

Key Entry Module.

SAE for DETAILS SHEETS. COMPONENT PRICES ft ORDER FORM.

HAVEN HARDWARE, Dept 32, 4 ASBY ROAD,
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ZX81 ZX SPECTRUM ZX81

GAMES

These are the best value for money games available. Don't be fooled by
trie low prices these are top quality games for use on either the ZX81
16K or the ZX SPECTRUM 48 K

til SUPERMIND An enhanced version of Mastermind

121 QUEST: As reviewed by SINCLAIR USER May

1962- Battle with The monsters in real time
and collect treasures) Fast reactions

essential I

13) REVERSE; Arrange a series of digits in ascending

order.

(4) STAR TREK The classic game! All the usual features:

8x8 galaxies, photon torpedoes, phasers,
Klingons, etc - a really good gamel

CASSETTE A iZXSl lGK) contains games 1 ,2,3 and 4 - ONLY £5,95
CASSETTE 8 (ZX SPECTRUM 48KJ contains games 1,2,3 and 4 -
ONLY £6.95

State Cassette A or B when ordering.
Post and packing included.
Orders to;

SERIOUS SOFTWARE, 7 WOODSIDE ROAD,
BICKLEY, KENT, BR12ES

ZX SPECTRUM ZX81 ZX SPECTRUM
ZX81 ZX SPECTRUM ZX81

■'■■■■ ■

*■»•■»■* + - r . r . , A , J J . , J . , - , - , -'- a .

4a

S [NCL A IR U S KR A u j,' u s H Wi2

helpline

File problems on
display in ZX-81

YOUR LETTERS are arriving
thick and fast and I am having
difficulty keeping pace with
them. I make a conscientious effort
either to answer letters individually,
via this column or by referring to
other answers in the column or
elsewhere.

All the questions this month
concern the ZX-81 display file in one
form or another. Before tackling the
first, let me review some fundamen-
tal ideas. The display file is the area
in RAM which holds the items which
are currently displayed on the TV
screen. During the program devel-
opment, for example, part of the
program listing is generally dis-
played and it is the job of the LIST
routine to copy the appropriate part
of the program area into the display
file so that it appears on the TV
screen.

The address of the beginning of
the display file varies with the
length of the program and so it is
held in the D-FILE system variable
and can be PRlNTed by entering:
PRINT PEEK 16396 + 256 *
PEEK 16397

Similarly, the address of the end
of the display is held in VARS — or
more correctly is one less than the
value in VARS — and can be
PRINTed by entering:
PRINT PEEK 16400 + 256 *
PEEK 16401-1

Each line displayed on the screen
is terminated by a byte containing
decimal 118 and there is one more
byte at the beginning of the file also
containing 1 IB. As there are 24 lines
in the display, there are 25 bytes
containing 116 and it is essential to
the correct functioning of the dis-
play software thai all 25 bytes are
present. If one or more is absent the
ZX-81 will almost certainly crash.

With an unexpended ZX-81 the
display file consists of those 25
bytes and no more unless a LIST.
PRINT or PLOT command has been
executed since the last CLS or RUN
command. That is a device to keep
the display file as small as possible,
thereby saving valuable space in
RAM. With a memory expansion
peck of 4K or more the ZX-81 pads-
out the display file with 32 bytes per
line each fiontaining zero — i.e.,

blanks. That mechanism creates an
immediate problem for users with-
out extra memory, as Michael
Wordruff of Accrington has dis-
covered, he writes: **I am having
problems with programs which
POKE the display because my ZX-81
crashes every time. For instance
5 LET Z = 1 + PEEK 16306 + 256 *
POKE 16397
10 POKE Z, 126
is a disaster. What is happening?"

Wordruffs routine is attempting
to POKE an inverse space into the
first PRINT position and it will work
well on a ZX-81 with at least 4K of
RAM because the display will be
padded-out with 32 blanks per line.
Without the extra memory, no such
padding occurs and so the routine
will overwrite the second of the 25
bytes containing 118, thus causing
the program to crash.

The solution to the problem and to
all similar ones is to create some
space at the appropriate position in
the display file by PRINTing one or
more blank characters. In that case
one space is required at the begin-
ning of the first line and so the
answer is to add the line:
2 PRINT "b"

where b represents the space
character.

"I would like to give a print
instruction conditional on whether
or not there is anything already
printed at the same position, I
solved the corresponding problem
by using PEEK 16438 and PEEK
16439 but the use of PEEK 16441
and PEEK 16442 does not work. Can
you help?" asks Brian OTJonnell of
Notiing Hill, London,

Page 179 of the ZX-81 Basic Pro-
gramming Manual shows that
addresses 16438 and 16439 in the
system variables area hold the x
and y co-ordinates of the lest point
to be PLOTed, as O'Donnell has dis-
covered. Unfortunately the equiva-
lent information for PRINT is not
stored. Instead the position at which
the next item will be PRINTed is held
in 16441 and 16442. There is a
further complication: the horizontal
PRINT position is counted from right
continued on pnj?e 4H

S I ST1L A [R USER A ugus N 9«2

47

■J J -

continued from page 41

to left and the vertical position from

the bottom upwards. Thus the

routine

10 PRINT 1 'HELP-LINE' 1

20 LET A = PEEK 16441

30 LET B= PEEK 16442

40 PRINT A. B

will print the values 33 23. The first

value, 33, indicates that the PRINT

have on his TV. He writes: ,4 I note
that my TV insurance cover con-
tains a clause excluding damage
caused by the use of TV games. Can
you advise if my ZX-81 can damage
my set?"

Television screens are designed to
reproduce as faithfully as possible a
picture of varying intensity. The
ZX-81 produces a more or less static

position is at the beginning of a line, image of uniform intensity. The only

i.e., 33 characters counting from
right to left from the beginning of of
the subsequent line. The second
value, 23, indicates that the line is
the 23rd from the bottom of the
screen because one tine has bean
used to PRINT "HELP-LINE". If line
10 is changed to
10 PRINT" HELP-LINE";
the values PRINTed are 24 24,
because the semi-colon prevents
skipping to the next line.

The following rather artificial
program PRINTs a new character
over the top of the last character
PRINTed:
10 PRINT AT 20,0; -ENTER

VALUES FOR '" "PRINT AT" " "
20 INPUT A
30 INPUT B

way in which damage is likely to
occur is if you leave the same image
on the screen for a long period with
the brightness and/or contrast
turned up.

En this situation it is possible that
the brightest parts of the image
become burned into the screen,
although with the normal black-on-
white display your eyes are likely to
feel uncomfortable long before the
screen shows any ill-effects; hence
while it is possible that the ZX-81
may damage the screen, damage is
very unlikely if you keep the bright-
ness and contrast at reasonable
levels.

"I would like to know if all the 1 6K
RAM packs on the market memory
map the video screen", writes Neil

PRINT AT 20,0: "ENTER A

CHARACTER TO PRINT"
50 INPUT Z$
60 PRTNTATA,B:Z$;
70 LET B = 32 - PEEK 1 644 1
80 LET A = 24 - PEEK 16442
£0 GOTO 40

The semi-colon at the end of line
60 is vital. If it is omitted the infor-
mation as to the position along the column that it is not possible to have

Davies of Cannock, Staffs. The
answer is yes; all 16K R AMs work in
the same fashion so far as the user is
concerned. The area between the
D-File and VARS addresses is
mapped to the TV screen.

Tha most interesting letter this
month is from Michael Sims of
Dundee. I wrote in a previous

line cannot be recovered from
16441.

Ken Hustwitt of Royston. Hert-
fordshire is worried about any
adverse effects his ZX-81 might

a Basic program longer than about
15K, even if more than 16K of RAM
is available, because the display file
will not function correctly above
address 32767 and the ZX-81 will

Not so, writes Sims.

"No crash occurs if the display
file is entirely below 32767 or
entirely above 32768 but a crash
will occur if the display file
straddles the two addresses and is
then displayed.

* 'The cure is sim ply t o ens ur e t ha t
when the display file nears 32767 —
check the VARS system variable —
you enter a huge line like:
XXXX LET ZERO = Q+ 0+ (T+ 0+ 0/
+ fr+ty'+ . . .

"With about 100 repetitions of
+ 0. such a line takes up more
memory than the display file when
in the program area but lists in less.
When NEWL1NE is pressed display
ceases while room is made below
the display for the program line to
be inserted, pushing the display file
entirely above 32768 before display
resumes."

I tried it and it worked. In case 1
was the only ZX-81 user who did not
know the trick. I contacted Bob
Branlon, the software expert at
Memotech Ltd, which manufactures
a 64K RAM for the ZX-81. It was
news to him, too. which made me
feel better. In fact, Bran ton was so
pleased with the idea that he has
sent the new Memotech high-
resolution graphics pack to Sims to
thank him for a neat idea.

The reason Sims' "huge line"
takes so much space in the program
area is because each is followed
by six hidden bytes, the first one
containing 126 and the remainder
holding the numerical represen-
tation of zero. 1 have described the
arrangement in previous columns.
The six hidden bytes are omitted
from program LISTings.

i Hwsrtn Consultant* lyuz.

• Pieuse address problems and quartet to
Andrew Hnwsnn, Hetpiine, Crnhnm Close,
Blawhurv. Oxfordshire.

46

SINCLAIR USER Auf-ufitl982

I
I
I

I
I

THE ZX BOOK CLUB

only

£5.95

DUE SEPTEMBER 1982

written by the man who helped write
the documentation for the ZX Spectrum:

LEARNING TO USE
THE ZX SPECTRUM
COMPUTER

by Robin Bradbeer, 100 pages fully illustrated.

This book has been written specially to help new and prospective
owners of theZX Spectrum to easily understand the operation and
full capabilities of this amazing new microcomputer.

* Provides clear descriptions of the hardware and functions,
describing use of the new keyboard, command keys and editing
facifities.

* Expla ins simp te progra m m ing using Sinclair BA SIC.
+ Describes graphics and colour faciiities in detail.

* Includes man y programs, including a nima tion,

* Appendices cover technical details and a glossary.

ALSO DUE SEPTEMBER 1982 - and also by Robin Bradbeer;-

LEARNING TO USE THE only-*— -._
ZX81 COMPUTER -FR QK

by Robin BraHbeer 100 pages fully illustrated. ak*# ■ *#%#

In the same series as the Learning to Use the ZX Spectrum, this new
book follows the same format, style and content and will prove an
invaluable guide for new (and experienced! } ZX81 owners.

Other bestselling titfes:-

Byteing Deeper into Your ZX81 by Mark Harrison

20 Simple Electronic Projects for the ZX81 by

Stephen Adams

Mastering Machine Code on your ZX81 by Toni Baker

The ZX81 Pocket Book by Trevor Toms

READ-OUT PUBLISHING COMPANY LTD

8 Camp Road, Farnborough, Hampshire, GU24 6EW Telephone: 0252 510331/2 Telex 858001 GOWER G

READ-OUT PUBLISHING COMPANY LTD

8 CAMP ROAD, FARNBOROUGH, HAMPSHIRE GU24 6EW.
24 hour answering service Telephone: 0252 510331/2

Name .

Address

Malm cheques payable 10 Head -Out Publishing Compsnv Ltd
I enclose my cheque Igr f .. ..

Please debit my Access [

E3

Nurtitter

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Signed
Date

"1 Please reserve rny copy/i&s of
71 Learning to Us* the ZX Spectrum

>u £595
H| Learning to Use the ZX81 r £5 95

^1 Please send me

copy fi« of

Byteing Deeper into Yottr ZX81
@£MI

20 Simple Electronic Projects lor
the 2X81 m £7 45

: Mastering Machine Code on Your
ZX81 t £850
□ The ZXB1 Pocket Book ■■« £6 95

I
I

I
I
I

SINCLAIR USER August 1M2

49

Disneytime cartoons come to
the land of the little Sinclair

Jack Knight considers that if it were not for the moving
characters, micros would lose much of their fascination

IF IT were not for the graphics 1
would not be as fascinated by
microcomputers as I am.
Moving characters and objects
around the screen and making them
work is challenging with only IK of
memory and without resort to the
complications of machine code.

The first thing to prove is that ob-
jects can be moved any way around
the screen. What is needed is some-
thing simple but realistic, something
which is in Us element whichever
way it travels in space. An aircraft?

No. speeding backwards it would
hardly be credible. So a helicopter.
To see what it looks like type-in the
following and RUN. The loop will be
needed shortly and we want its
character co-ordinates to look at the
graphic.

In all that follows, unless it is
stated, the Vs stand for spaces.

i« for i_ .« ro* as

M PRINT HT B,t-l"

',TM L,

RUN, Simple, easy to play with,
but with a passing resemblance to

what is intended. Before you rush in
with the NEXT statement, be pre-
pared for a program short of per-
fection, but RUN it as it is. es there is
a purpose. First;
30 NEXT L
RUN

It is a case of "tear along the
dotted line 1 '. My intention was to
emphasise the need for an eraser, a
space or spaces to rub out the
cheracterfs) left behind as the
graphic moves along. Edit line 20 by
inserting a space after the first
inverted commas, That is the eraser
but you have not finished yet. There
is a need to include another space at
the beginning of the second part of
the graphic, otherwise the heli-
copter will be lopsided, RUN.

The difficulty you have had edit-
ing a line you have only just typed-in
will be worthwhile as a reminder for
the future of how essential the
eraser is.

Another thing to remember from
the program is the TAB sta tement. It
caused the body of the helicopter to
be printed on the next line. The rule
is that PRINT stays on the same line
unless that would involve back-
spacing, when it moves to the next
line.

So what about bringing the heli-
copter back across the screen?
Delete line 10 and replace it by:
10FORL= 26 TOO STEP -1

The eraser? With line 20 a space
is needed at the end of each of the
two parts of the graphic. RUN.

To make the aircraft move up the
screen, first replace line 10 by:

10 FOR L = 19 TO STEP -1
Then change line 20 to:

sw> pnim jit L,»i *—■-.•*;«■ *
3, ■■u*ii"iT« 13, "IP spfleeflj"

RUN
That is the least successful

50

SINCLAIR USER AukusI J982

direction to move a graphic, for
technical reasons. Before leaving
this program, notice the string of
erasers inserted to clean-up after
the graphic.

To complete movement in the four
main directions, the helicopter
needs to be brought down the
screen. Replace lines 10 and 20 by:

moving
graphics

decreasing. Type-in:

. T«tJ 19-L, ---.--".TM

(6 SfiaCESi

RUN

Notice that once you know how. it
is easy to handle increasing and
decreasing numbers at the same
time [Land 19-L],

Before we leave the helicopter let
it show us its profile, hovering,
rotars turning. Alter the last part of
the graphics of line 20 and type-in
new lines as follows:-

Sf FBIN1 HI L • _■ ' '

B 1-S-L i "--=--■■ .TAB 19-1. = :M
3* FOB H.i TO liStf
4ti» OfiJfMT AT 1 ,J«; "--", TAB **;

'.ii.i-

9.^ PRINT BT J.1B,
&0 NEXT H

"tAl" TAB JS;

ifi FDR *. »« TTjl L4

SO PRINT flT_L.^l».; "is. .S^B* 7 !

to© 13 J

We have not finished yet. It is
also possible to move an image diag-
onally up or down the screen in
either direction. Staying with our
patient helicopter, we will try one of
the more difficult — that is from the
top right corner to the bottom left; it
is difficult because character co-
ordinates must be used with the one
increasing and the other

RUN

Finally, having experimented to
lay the groundwork, that is the mo-
ment to run an animated cartoon,
but do not expect a full-length
feature — remember it is only a IK
RAM. Perhaps, however, it will set
you on the way to designing your
own graphics.

Before you RUN the cartoon, here
are some hints, as you will be hard
up against the limit of the memory.
Operate NEW before you start, to
clear everything first If you need to
EDIT and the ZX will not bring down
the line. CLEAR and then operate
EDIT i mmedi a tel y. I f the g raphi cs do
not look correct. go over the
variables, check the number of
spaces and the characters to shake
out the bugs.

RUN
It has probably already occurred
to some that it should be possible to
fly the machine around the back of
the screen. So add:

4,8 CLS

S« FOP L - 1- TO B*

aa next i_

RUN
The PAUSE statement could have
been used instead of lines 50 and 60
but an empty loop has the advantage
that it is free of the irritating flash,
The count from 1 to 50 is appro-
ximately one second — the same
number of screens per second on
British TV.

200

210

PRINT BT S,S; "BOOHEBftMS"
PAUSE 75 ^^

print bt is, i_; ft*; trs L.;"VUy|

" TAB i- ', "'.flMHMWMH""

NEXT L

PAUSE S0

FOR £_=£* TO 30

prx^t at j«,1-;"Mi

PRINT AT IS r '3l;"'J"

FOR L.-I TO 13

PRINT BT 1!p ( L;"^"

NEXT L.

PRINT BT ie#*»#"V

PAUSE BUS

PRINT AT l5,i4-;"tD

le; a*

print It is , as; "*J" ; tab is; "

PAUSE 1*0

PRINT AT 10, I£, "THE END"

spaces.*

SINCLAIR USER August 1962

31

New ZX8I Software
from Sinclair.

A whole new range of software for
the Sinclair ZXS1 Personal Computer
is now available - direct from Sinclair.
Produced by ICL and Psion, these
really excellent cassettes cover
games, education, and business/
household management.

Some of the more elaborate pro-
grams can only be run on a ZX81
augmented by the ZX16K RAM pack
(The description of each cassette
makes it clear what hardware is
required ) The RAM pack provides 16-
times more memory in one complete
module, and simply plugs into the rear
of a ZX81. And the price has just been
dramatically reduced to only £29.95

The Sinclair ZX Printer offer full
alphanumerics and highly-sophisticated
graphics. A special feature is COPY
which prints out exactly what is on the
whole TV screen without the need for
further instructions. So now you can
print out your results for a permanent
record. The ZX Printer plugs into the
rear of your ZX81, and you can
connect a RAM pack as well.

Games

Cassette G1 Super Programs 1 {ICL)

Hardware required - 2X81.

Price - £4.95.

Programs - Invasion from Jupiter

Skittles, Magic Square. Doodle. Kim.

Liquid Capacity,

Description - Five games programs

plus easy conversion between pints/

gallons and litres.

Cassette G2 : Super Programs 2 (ICL)
Hardware required - ZX81
Price - £4.95.

Programs - Rings around Saturn
Secret Code. Mindboggling. Silhouette
Memory Test. Metric conversion.
Description - Five games plus easy
conversion between inches/feet7 yards
and centimetres/ met res

Cassette G3. Super Programs 3 (ICL)
Hardware required - ZX81.
Price - £4.95

Programs - Train Race. Challenge.
Secret Message. Mind that Meteor
Character Doodle. Currency Conversion.
Description - Fives games plus currency
conversion at will - for example,
dollars to pounds.

Cassette G4 : Super Programs 4 (ICL)
Hardware required - ZX81 ,
Price - £4 95.

Programs - Down Under. Submarines
Doodling with Graphics. The Invisible
Invader. Reaction. Petrol.
Description - Five games plus easy
conversion between miles per gallon
and European fuel consumption figures

Cassette GS: Super Programs 5 (ICL)
Hardware required - ZX81 + 16K R AM.
Price - £4.95.

Programs - Martian Knock Out.
Graffiti Find the Mate.
Labyrinth. Drop a Brick
Continental.
Description - Five
games plus easy
conversion
between English and
continental dress sizes

Cassette G6:
Super Programs 6 (ICL }
Hardware required - ZX81 + 16K R AM.
Price - £4.95

Programs -Galactic Invasion, Journey
into Danger. Create Nine Hole Golf-
Solitaire Daylight Robbery.
Description - Six games making full use
of the ZX 81's moving graphics capability.

Cassette G7: Super Programs 7 (ICL)

Hardware required - ZX81.

Price. - £4.95.

Programs -Racetrack, Chase NIM.

Tower of Hanoi. Docking the Spaceship.

Golf.

Description - Six games including the

fascinating Tower of Hanoi problem.

Cassette GC Super Programs 8 (ICL)

Hardware required - ZX81 + 16K R AM.

Price - £4 95.

Programs - Star Trail (plus blank tape on

side 2),

Description - Can you, as Captain

Church of the UK spaceship Endeavour,

rid the galaxy of the Klingon menace?

Cassette G9: Biorhythms (ICL)

Hardware required - ZX81 + 16K RAM.

Price - £6.95.

Programs - What are Biorhythms?

Your Biohythms

Description - When will you be at your

peak (and trough) physically,

emotionally, and intellectually?

Cassette G10: Backgammon (Psion)
Hardware required - ZX81 + 16K RAM.
Price - £5 95.

Programs - Backgammon. Dice.
Description - A great program, using
fast and efficient machine code, with
graphics board, rolling dice, and doub-
ling dice. The dice program can be
used for any dice game.

Cassette G11: Chess (Psion)
Hardware required - ZX81 + 16K RAM,
Price - £6,95,

Programs - Chess Chess Clock
Description - Fast, efficient machine
code, a graphic display of the board and
pieces, plus six levels of ability, combine
to make this one of the best chess pro-
grams available. The Chess Clock
program can be used at any time

Cassette G12:

Fantasy Games (Psion}

Hardware required - ZX81 (or ZX80

with 8K BASIC ROM) + 16K RAM.

Price - £4.75

Programs - Perilous Swamp. Sorcerer's

Island.

Description - Perilous Swamp rescue

a beautiful princess from the evil wizard.

Sorcerer's Island: you're marooned. To

escape, you'll probably need the help

of the Grand Sorcerer.

Cassette G1 3:

Space Raiders and Bomber (Psion)

Hardware required - ZX81 + 16K RAM

Price - £3.95.

Programs - Space Raiders Bomber

Description - Space Raiders is the ZX81

version of the popular pub game

Bomber: destroy a city before you hit a

sky-scraper.

Cassette G14: Right Simulation (Psion)

Hardware required - ZX81 + 16K RAM

Price -£5.95

Program - Right Simulation (plus blank

tape on side 2)

Description - Simulates a highly

manoeuvrable light aircraft with full

cont rols , i nstrume n t at i o n , a vi ew through

the cockpit window, and navigational

ards Happy landings!

Education

Cassette E1; Fun to Learn series -
English Literature 1 (ICL}
Hardware required - ZX81 + 16K RAM
Price - £6.95

Programs - Novelists. Authors
Description - Who wrote 'Robinson
Crusoe'? Which novelist do you
associate with Father Brown?

Cassette E2; Fun to Learn series -

English Literature 2 (ICL)

Hardware required - ZX81 + 16K RAM

Price - £6 95.

Programs - Poets, Playwrights Modern

Authors.

Description - Who wrote 'Song of the

Shirt? Which playwright also played

cricket for England?

Cassette E3: Fun to Learn
series - Geography 1 (ICL)
Hardware required - ZX81 +
16KRAM.
Price - £6-95
Programs - Towns in England and
Wales. Countries and Capitals of Europe
Description - The computer shows you
a map and a list of towns. You locate
the towns correctly. Or the computer
challenges you to name a pinpointed
location.

Cassette E4: Fun to Learn series -

History 1 (ICL)

Hardware required - 2X81 + 16K RAM.

Price - £6.95

Programs - Events in British History

British Monarchs.

DesCription - From 1066 to 1961. find

Out when important events occurred

Recognise monarchs in an identity

parade

Cassette ES: Fun to Learn series -

Mathematics 1 (ICL)

Hardware required - ZX81 + 16K RAM.

Price - £6,95

Programs - Addition/Subtraction.

Multiplication/Division

Description - Questions and answers

on basic mathematics at different

levels of difficulty.

Cassette E6: Fun to Learn series -

Music 1 (ICL)

Hardware required - ZX81 + 16K RAM.

Price -£6 95.

Programs - Composers Musicians,

Description - Which instrument does

James Galway play? Who composed

'Peter Grimes 1 ?

Cassette E7 : Fun to Learn series -

Inventions 1 (ICL)

Hardware required - ZX81 + 16K RAM.

Price - £6 95

Programs - inventions before 1850.

Inventions since 1850.

Description - Who invented television?

What was the dangerous Lucifer?

Cassette E8; Fun to Learn series -
Spelling 1 (ICL)

Hardware required - ZX61 + 16K RAM
Price - £6.95.

Programs - Se rie a A1 -A1 5 . Series B1 - B1 5.
Description - Li ate n to the word spoken
on your tape recorder, then spell it out
on your ZX81 300 words in total
suitable for 6-11 year olds.

Business/household

Cassette B1 : The Collector's Pack (ICL)
Hardware required - ZX81 + 16K RAM-
Price -£9.95.

Program - Collector's Pack, plus blank
tape orside 2 for program/data storage.
Description - This comprehensive pro-
gram should allow collectors (of stamps,
coins etc) to hold up to 400 records of
up to 6 different items on one cassette.
Keep your records up to date and
sorted into order.

Cassette B2: The Club Record

Controller (ICL)

Hardware required - ZX81 + 16K RAM.

Price - £9.95.

Program - Club Record Controller plus

Wank tape on side 2 for program/data

storage.

Description - Enables clubs to hold

records of up to 100 members on one

cassette Allows for names, addresses,

phone numbers plus five lots of

additional information - eg type of

membership.

Cassette B3: VU-CALC (Psion)
Hardware required - ZX81 + 16K RAM
Price - £7.95
Program - VU-CALC.
Description - Turns your ZX81 into an
immensely powerful analysis chart,
VU-CALC constructs, generates and
calculates large tables for applications
such as financial analysis, budget
sheets, and projections. Complete with
full instructions-
Cassette B4: VU-F1LE (Psion)
Hardware required - ZX81 + 16K RAM
Price - £7 95

Programs - VU-FILE. Examples.
Description - A gen era I -purpose infor-
mation storage and retrieval program
with emphasis on user-friendliness and
visual display. Use it to catalogue your
collection, maintain records orclub
memberships, keep track of your
accounts, or as a telephone directory

How to order

Simply use the FREEPOST order
form below and either enclose a
cheque or give us your credit card
number. Credit card holders can order
by phone - simply call Camberley
(0276) 66104 or 21282 during office
hours. Either way, please allow up to
28 days for delivery, and there's a
14-day money -back option, of course.

laii-

iini

ZX8I
SOFTWARE

Sinclair Research Ltd.

Stanhope Road. Camberley. Surrey,

GU15 3PS

Tel: Camberley (0276) 66104 & 21282.

To: Sinclair Research, FREEPOST, Camberley, Surrey. GU153BR
Please send me Ihe items I have indicated below.

at*

Cassette

Cone

Item

price

Total

Gt Super Programs 1

30

£4.95

G2" Super Programs 2

31

LA 95

G3 Super Programs 3

32

£4 95

G4 Super Programs 4

33

£4 Hh

GS Super Programs 5

34

414 95

Gfl: Super Programs 6

3H

£4 95

G 7 . Super Programs 7

Ah

£449

G6: Super Programs 6

37

£435

G9 BiorhylhmSi

38

£ft8S

G.1Q: Bfflckgamrnon

39

£595

G11 Chess

40

£M^

G12 Fantasy Games

41

L4 75

G13- Space Raiders. & BdrntJW

*j

ease

QM F light Simulation

43

£565

|Sisri Literature 1

44

K&85

Oty

Cassette

Code

item
price

Tolnl

F2 English Literati" 2

45

£695

E3: Geography 1

46

E4 History 1

47

i e Bi

E5: MBttarnaltcs t

46

£&ee

ES- Music 1

*9

c&aa

£7' Inventions 1

BO

£695

E6 Spelling 1

51

ti-j'rZ.

B1 CoUKtori Rk*

52

Eft 65

B2- Club Rsconl Controller

53

i ■■!■<:

B3 VU-CALC

54

l.r.H,

56

i. .■ MS

ZX ItiK RAM pack

18

turn

Jf. Printer

■?>

JL&!> Lr r j

Posl & packing -

■Cwiry if nr<tei ing hardware

£295

TOTAL C

I enclose a cheque/postal ofder to Sinclair Research Ltd for £
Please charge my *Access/Barclaycard/Trustcarct no
"Please delete as app/rcabte- I 1 I I I I I

i Mr/MrSLM'&S | | I I I I I I 1111

I Addr ess I I I | | I I I I I I I I I I I

1 I I 1 I I

I I I I I 1 I

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COMPUTACALC ZX

laftTQHGEieT'u? 167. 16? L67 : 1*
>HONE 4 3 35

ELECT.

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364

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S84

:«7

An advanced spreadsheet program for the Sinclair ZXfll
with 16KRAM.

This versatile software allows m angulation and inspection
of data in the most convenient way aver. Ideal for financial
planning, personal budgeting, cashflow analysis and count-
less Other business, home, scientific and technical
applications

The screen acts as a window on a much larger grid ^up to 3 8
x 38) of titles and numbers I up to 9 digits). Changs one
number or formula and all dependant results change auto-
matical lv Save on tape or printout for a permanent record
Tasks that would take hours with penal paper and
calculator can be performed in seconds with
COMPUTACALC ZX.

Cassette and booklet - £7.96. Available from W.H. Smith r
Better Computer shops and mail order from SILICON TRICKS,
Depi S7 2-4 Chichester Hants , London WC2 1EJ. (Tel: 01-603

60741

NOW

AVAiLABLE

&P6CTRACALC lor

Specmjm 16K &«K -

r All teal urea of cornpiJtatalcZ) 1 ;
and mere - El 2.96 mail orda- only

zxai & ten
THE TOMB OF

DRACULA!

&

\

&X> HORROR ADVENTURE GAMEl

Occupying over 13v'jK ol memory, a superb 3D graphics
adventure game for the 2X81 with 16K RAM. for only
£3.95! Enter Dmcula's tomb at 30 minutes to sunset ,
wan der through the tomb's pra-mapped 300 vaults in
search or ihe fabled Vampire's Treasure pick up valuable
silver stakes and use them !0 defend yourself against the
lurking horrors . . . ghouls, zombies, pitsot primaevalslime
See them all on the ZXSI's plan of the tomb , when it
will let youl Take a chance on a Mystery Vault . if you dare!
And all the time the minutes are ticking by to sunset
when Dracula rises from his coffin and comes after you !
Eachof the infinite levels of the tomb has itsowii 300 vaults
go as deep as you like. Ihe Prince ol Darkness will seek
you out in his blood-lust 1 WARNING; people of an
exceptionally nervous disposition should play this game
only during the hours of daylight ! Special facility enables a
game in progress to be saved on tape so vdu can continue it
whenever you choose

Price of only £3.95 includes ready-to-load cassette with
library case and inlay, full instructions, postage and packing

Order today' Money refunded if not delighted 1 Send cash,
P.O.Orchequeto:

MOVIEDROME VIDEO IDept SU3I
t9 Leighton Avenue, Pinner. HA5 3BW.

MICROWARE

Retail Shop In LEICESTER
for SINCLAIR Computers

Keyboards/ Ram Packs, 1/0 Ports,
Monitors, G/Roms; Games, Serious,
Home/ Business, Education Programs;
Books £f Magazines,

Also — Now stocking Books and
Software for SPECTRUM, BBC and
VIC 20.

MICROWARE

131 Melton Road

Open

Closed

Leicester

9.30

Thursday

Tel: 0533 681812

5.30

MICROWARE

it 1 471

:!•!•] a

ZX81 USER'S HANDBOOK

Trevor J Terrell and Robert J Simpson

ZX81 owners wishing to learn more about their
computer will wanl (his book It answers many
questions about BASIC and machine code
programming, and n explains Ihe ZX81 hardware
and how n operates Programs in BASIC and
machine' code are included, to illuslrale many of
the points covered in Ihe lext and to help readers
develop their own programs.
408 01223 4 144 pages appro* £4.95 appro*

:^tl*;di:ii3:i*=ii

ZX81 BASIC BOOK Hobin Norman

Covers ihe Oasic 1K version, the additional faciltiies
offered oy the 16K expansion RAM and how to use
ihe Sinclair ZX Prime? There are 14 original
programs for you to run on Ihe machine (for 1 K and
16K versions), and for those contused by computer
jargon (arid who isn't?) there Is a glossary of
technical terms, Robin Norman assumes no mjlial
knowledge ot computing and his undemanding
writing style is perfecl tor a beginner's introduction

408 011 78 5 1 76 pages C4.95

QftQEB NOW '

■
arted I ■ ■ I ■' Ml* [.4yflWi»

ewnes Technical Books

i Li.". ..j'

.

14

SINCLAIRUSER August 1982

inside

Sinclair

Claudia Cooke talks to Rick Dickinson, Sinclair industrial
designer, who won a Design Council award for the Z.X-81

Modest award-winner sets
the pace in micro design

_ . .. * 11 m ^..>ntlA '. ,-h A n u 1 t i a

AWARD-WINNING industrial
designer Rick Dickinson is
modest about his achieve-
ments, which so far include the
ZX-81, for which he won a Design
Council award, and the Spectrum,

'*I don't think 1 have ever been
delighted with anything I have
done"", says this blond, 26-year-old
prodigy. "There always seems to be
room for improvement".

Dickinson is a meticulous worker
and while both the ZX-81 and the
Spectrum are selling beyond all
expectations, he adds. *'I would
never let anything go to production
unless I wes happy with it".

SINCLAIRU5ER August 1982

Graduating from the Newcastle
Polytechnic pioneering industrial
design course, Dickinson and his
classmates are equipped, theoreti-
cally, to design anything "from
knives and forks to ocean tankers",

Dickinson produced items as
diverse as a chain saw and a road
tanker during his first year as a
qualified industrial designer, which
he spent freelancing in Wales.

He had already spent some time
working for Clive Sinclair while he
was studying for his degree and it
was not long before he was
absorbed as a full-time member of
staff and the company's sole

industrial designer. He is
responsible for the appearance of
Sinclair products down to the layout
of the components inside and the
pattern of information on the
keyboards. His membrane keyboard
for the ZX-8 1 was revolutionary and
largely responsible for the low retail
price of the product.

Dickinson has learned that price
is the ultimate justification end on
all his designs he has to bear in mind
the cost factor as well as the
straightforward appearance of any

item.

The membrane keyboard was e
continued on page 56

55

continued from pufie 55
great success and Sinclair has had
to cope with numerous pirate copies
since its inception but, as with
everything, it had its disadvantages.
Its main disadvantage was its in-
ability to register touch. To ensure
you have a response it is necessary
to look at the screen — there is no re-
assuring click when you touch each
key.

For the Spectrum, Dickinson has
returned to a raised keyboard but
again he has produced a first by
making it from rubber,

He says: "I like the Spectrum
much more than the ZX-81. It was
much quicker to design but much
more complicated. It is a step up-
market and I was really trying hard
for a super-smart machine, It is not
for quite the same amateur
market".

The process of design is a long
one. Normally it begins when Clive
Sinclair outlines his idea to Dickin-
son, including his demands about
size. "He will resolve in his own
mind the specifications and he will
always say how small it has to be. I
think how can it be that small? Yet
he is always right in the end and we
produce something which seemed
impossible to me in the beginning".

Armed with his brief, Dickinson
then spends a few days with his
sketchbook, exploring ideas, but he
likes to begin work in three dimen-

SUc.ti Dickinson uf wurk in his workshop.

possible place. Perhaps the most
difficult part is the keyboard,
Dickinson says: "We spent a great
deal of time on that. It is the only
interface between the user and the
product and it has to be right. We
were trying also to cram on more
information than anyone had every
done. I believe that form should
follow function".

Design of the ZX-81 took about six
months in all. The Spectrum was
quicker but with all his major
projects Dickinson also has to set
aside lime for add-ons to existing

That is the exciting thing in this company;
many products are the first of their type
so you are in on something new.'

sions as quickly as possible and is
soon modelling in Perspex or
plasticine.

The next stage is to produce the
finished model in Perspex but
obviously it has no components
inside — it is produced as a solid
block.

That model is detailed, even down
to the graphics which Dickinson has
painted on. Layout of the interior
follows, with the designer using all
his powers of logic to ensure that
each component is in the best

computers — the work is never
finished. His main project now is the
flat-tube TV, expected to be
launched later this year.

His biggest problem with that is
that Sinclair has already been
working on it for some time.
Normally he is briefed at the same
time as the electronic engineers but
this time the inside is already
finished. It is also another first,
which means Dickinson cannot
research by looking at existing
products in the field.

"That is the most exciting thing
with this company, you know; many
products are the first of their type,
so you are really in on something
new".

Dickinson is content with his life
at the moment in every way. At
school he liked the sciences and the
arts and his job ensures that he
remains involved in both. He spent
one year on a foundation course at
art college at Grimsby before
starting to read for his degree and
feels the experience was invalu-
able. He is happy with his work at
Sinclair. When he started almost
three years ago the staff numbered
five. Today it is 30 and the company
is going from strength to strength,
crushing the effects of the recession
as it marches on.

"We all work very closely, very
much as a team. Most of the informa-
tion is in people's heads. There is no
time to be formal and put it down on
paper. It is a good atmosphere in
which to work".

For this award-winning York-
shireman, it abounds with oppor-
tunity, too. He has already entered
the Spectrum for this year's Design
Council awards and on his drawing
board are the initial stages of the
flat-tube TV — another first, and
possibly another award.

SB

5INCLA IR USER A uj< u s M HBJ7

ZX81 M.C.

16K
SOFTWARE

ZXC ARCADE PLUS PACK:

SLOT — A graphical simulation of 3 fruit

machine With Hold and Nudge features.

BRE AKOUT ; SUPER PROGRESSIVE BREAKOUT

DODGEMS - with increasing difficulty Can you

evade the computer cars and clear all the dots,

LIFE - On a maximum 64x48 screen grid

Send cheque, postal order for £7-95 to:

A. READMAN
SOFTWARE,

16 South Row, Bdon. Biship Auckland. Go. Durham

DL14 BUT

Mail order only, trade enquiries welcome

J

RENUMBERS THE PARTS OTHER
PROGRAMS DON'T REACH

ZX81 RENUMBER-DELETE

Tucked safely away in high memory this fast M/C program really lives

up to its name. Select either blocks, single lines or the whole program.

Specify the START number, the NEW start number, the INCREMENT,

and the STOP number, HIT the KEY and its ALL DONE By ALL we

mean ALL GOTOS. GOSUBS. LIST. LUSTS. & RUNS which have branch

addresses in the affected region, DELETE allows you to select LINES

or BLOCKS and INSTANTLY remove them trom the program VERY

FAST no waiting, an extremely well written program, £600 including

VAT, and POST,

Z X81 - TOOLKIT

Along with RENUMBEWDELETE. a lurther 3 utilities are included to
make this a must for serious programmers U) FIRST REM EXPANDER
Expand the first REM by any specified length Easy to use, Type 1 REM
followed by any CHARACTER. Call the EXPANDER SPECIFY the
number of BYTES lo add. A few BLINKS later and it's DONE. {2)
DECIMAL REM LOADER Use this to load DECIMAL CODE into the first
REM ALLOWS use of the existing line edit facilities, So easy to use. (3)

66 BYTE MEMORY LISTER Start where you like. Specify the start

address and immediately the contents and locations of 66 bytes will be

DISPLAYED or PRINTED. One SINGLE KEYSTROKE will then page

FORWARDS of BACKWARDS as you wish. Well written in MJcode

USEFUL AND FAST TOO"! E8.Q0 inclusive. If you re not convinced

send £1,00 and we'll send the instructions. If you buy wrthin 14 days

you can deduct the £1,00.

WORK FORCE. 140 WILSDEN AVE,

LUTON, BEDS LU1 5HR,

ZX81 HEWSON CONSULTANTS ZX81

HINTS AND TIPS FOR THE

ZX81 by Andrew Hewson £3-95

°»Oj- Cd*" il>,'*> ■*»* i fa ■

Th. men compltll book >l <h# B'lcr

nUpj|rT~"r J ~ J *'~l "v* lu ■**j*w* * Eo^nu'-np n„i'l uul & I ^ "« '" M""l

nfl:'^»■^~*SB#^»-■>Li' , M» ^ * lH, ■ l ***' "" ,

ulM .,l,nn, IMDW. '- ■ +***• «#» '■" •■ "•■*"« ;*'"•*
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prt**", -«*-«■ •* MltiJ.WIV'l:""-!""* "■ ""'<* 11 ""
V« ( di nl p^Wllxil I 'BO HW™ CHJP.im pngXCT I ,.

.^MnnrfraJWHH rgd.nl « MpcnrftiCOTrl ■"°i|]'»i *"»'

■T "■ ' *** »-■— ™ «*»■«■' > *»wim

16K MEMORY

'he B(v: .i.u(!OH»OM - I**

64K MEMO PACK

■J t-i, '$^miM*B ■ ■.*

ft r *K "|^<.rj*|*wr>^mjl^i»'t»ci.i.-w«*>-ipH[Kjmlnim*«.y-- 1 '

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■ft 3JH'**mpi**l-
13 &*■ 'ilP'l M<*'

£79,00

£26.95

48+8K NEW

B 'I""'

■JAM *-r .-J'Ptrwif tat-Aofli-'ij
yi-jg»,,mi,r»i*-T'c4Mitrw r.i -
ViiHi mjKfirf^c** rwihn**r r*

ZSO OP CODES

£1.45

A AUII ID. [*♦ IMOMinjr .1,4 Tilt oppNMlCHl p.,,,)!.!™.

.I,k* Tt,™ h.im riHfc ntkor-er mi. m SOO pM ao
m„ h,n. lhK 1M if"Ci.or« '" HtcmM i"d lmiia.c«M« will>
,h,„ mwrMici tj^h Op Cadi m wincm nm.iind *nd
CHO-nraWKV* Suppl.ni .n ■ ^it"*"'™! l'KiIP* r " r, l *'*"*'
lar im> .■"■■nic* «^4 rJ\ji»o^itir

PROGRAMMERS
TOOLKIT

£6.50

it**/?*"! ■ , Mu*CB" F TflurH|ih"1 , «rtTW>i^r>'

. w%l«ri'iJll t «'

■ PiififcTft^n -

■ ,,0*,-!^ U *,^ .-viuu-^iitr^ih- lu
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tb^JHSw Ml wbns nraowwI'—'M"*".*.. t«.f*gpW»i»nrt.

. -A l..-|L|. I i I"

■ ■«ulili'«','n [ i J rt«gi--i1»ll.Mrtr^l--*"'L,rjro .indliQSL*! I

" D[ n *1 irf. i i.i -i « i l>. i ■^*"' 1

■ jal" "n . mi ,m. ntutnd * • i**m* *um*m "•*>* mi**-: voir'-

PUCKMAN NEW!

AH J'M'UI' di4pli>
iCOUi l^a rnij-i 'u* IciDQ
Dudfl*ir^H nhrj^ipwhrjcwri*
bo devwi» vuu

*,_,|,nm#Eii L-pi-or, - |+ip

FjM k<fritlO.ViS di»iJl*H
ft uN .nitrvi:Ciim dlipllY
Canlinupwi «D¥ing
H*<i int bill ftf "■ M u^f*
^upii 1 Bf*p*iic* whi-n ufrn

*»lh Ouith Si'mJ urjphH*

bturd

PILOT *
* NEW!

>r-> ii-ini-b.-i "y ^MftMPl*|l*

,/,. lUI-lluH ll,MIWM"Mit*1|

MMiilWXlltimUMrillftJtW

,.■.1 HfKtjpnH Lr-l-pfJ* *•-**>

L F*Mrrp*l .uuHilpKiWlW"!***
(Bill - ir*«li"**l HT» |Nt»¥*^

.Akm.ccjwik Cmv fen*-* 1 *uio*^r

jgiM.^IWliMI Ir.BT.HIIH-r-D.r

„1, nni(i«^ □ »\j'Ti^K itukSm. A
<MMi wN ' -Jrt bl PT«* IB l«* t(-"

,^rrtk#*f*Tt#cfttoft*W«IMi"lft

.nnLHcuNi lafiLjifi rixji ■**** G"Wl

.. I 0*|ifcv hl **>'Hr +h » V

- PrttDifefrK p■ui^■ f •'^ E ' T ^ ,, *• , ■ r '

■ . ..I- -"rlpUkrt-i

£61 95

41 «□ i*.t fa* run t*f ALODUI O*

LO HtWSON CONSULTANTS. &cp' EC, r»A St HHV i

Sirtll W#l«"Hj'° r rJ- 0"«ni 0*10 Of I

SINCLAIR USER August 1982

57

SINCLAIR

16K RAM

DOWN TO

£29.95

Sinclair

W:

microcomputer

now at x

Cambridge Computer Store!

MtMWMwmm

ZX81 Assembled
ZX81 Kit
16K RAM
Printer

£69.95

£49.95

£29.95 hew price

£59.95 new price

Alt units now in stock

Wide range of books, software

and DCP packs also available

in our "Budget Micros 1 department.

Cambridge Computer Store

1 Emmanuel Street, Cambridge CB1 1NE

Phone (0223) 356264/65334

AFso: Acorn Alom * VlC-20 ■ Tandy TRS-80

fir

/Mil
ZXU

ntsta

VIDEO GENU

* IS U J \ \ St

^atf

\M>\\ AS }(H

& ftt-n-'t, Mi(>\

**' (i {{ H'li t utti s*

* IHA. Wfl fi \t-\Xht I

^P^:

* i\Jt fni s

* 7 LEVELypF'P LAY
* SAVE I, \\!i t it it in

It MA\A(,t i ti A I HlilXi,*

A- /'ICE YOUR TEAM EOH EACH MA lilt* I \. it t>*

I hi* |A||| a miTi' %iinutiitii>rt. I hit is an ^tiling anil hijfhlt tnj.n jhk

isamc in whiih him pl*s il., ^ Jr i n \ j h«H)lhj|l Muri^ir tiipin K »nli ihc

pmhk'ms and drii^i mis, imoki'd in running ii*u,r iluh. I luri jrc s<> mjnt

I til lift*, il la iinpusiihlr In lisl Ihrm llcrr but intluiM urr |i>rm I l"|i

li'iltni NUttM \ I l.\ win I. gin nl* hilling*, nafci* bilk In pji , and urn < j«

nrn bt -jiLi-d! |l is, j E jiiic nruulriny, a ^rrjl drill <>l skill,, jml pt'ippk

pi j i il fur \,\yttf\\ lu>nrs un i'nd Ivii 1 hji*r pnml!).

WK dl AH AN I M-. Ihjl rhi% is tmr "If Ibr hrsl I'timputrf Kurnrs ipiuS*

i'ht plju'ri!

HI. I HKW^HJ. Urn turn* h rMn-mili •MMNjl

looiiiAi i m\s\(,i-:k

IS U PPitl II HlfH ISMHt < itnw

jji i ; wj.s mi t \n/n >n*. tt nr

HA Rim ARK HKUriRKH

/.Mtli

/ \ in
HA H(t\l
H>r\ H t\)

IH.SJM

ft \ f i II

l,i itrtSfr tentf ( rttnlir.'P O. C7 BS
mrfift frtyatitr tv A DDIt T! I E l,AWJ
*i, ititpi \.i. p.o. sax JJ»

PI f-.<SJ \; I II I C r\f/'l ,'^A

EDUCATIONAL COMPUTING

en ihe

X81

GAMES PACK

Rtair ,'Fi..s A„r vhi.ju ' f .vi> I li(i
1 D BbIIIb IM., ,:Ip 1K|

*.,p UriH iBflsic. * "todi i«Hi

■Sn*t*.&l!.i l«Kl

'i»mi l«pt1slBj3i.:6 M.'com lB«t>
smoi itiiuc ie*i

V*L* Mo4« iBlEIC l-EKl

NVf * Jut. A «' Of prufrvninii r» luin |gui

S"ii-a» 1XH i.ira a umifliil aducafKHi*' too'
And fou tfan'r **»t n#»d jo jtjiaiv p's^rimjninv.

Tnan «r« CJ»I* Inil'uclmni ind f>H«n( f of dipt
A •drJM D*Ufjn«tf Id gatmfBmi drill A p'jr.'ic*
1*4 prwnora <*«rmng through Infraction t «Haw,

Includes -

A Sl'TipllllPCl

sfetsion of The
fanioui Tufile

CODED MISSILE

Combines, the
fun of arcade
games with
learning

£4.95 only

incf o & p

Graph-pbtter • h^ipgr^m • SimQn-sjwLI • £U<chUtfr(J • 1 imcs idLir • Kelt
Sw'K-qii« • XY cnarflhnjtts ff> C*uni • Equslions* Ar«»f> Guss-a-Volumt
Angles • Opsi^ii-0own>id,i; ■ Music -mi*' • S^f Sm • Wpe-oul •Spell
l€<D|K'*liire • ClQLh • Muniiy • ^.fitkr P" f^k | ■ _("""■> JL f*| p
■VdSttrnund* nkumher stiool • + 26 mart (■■> l^r ^^ \^ f^ rV I—

AW programmes
til I K

Creative use ot
graphics

Many innovative
ideas

Fully documented

Includes meny
games

To

| Hiftase sflnd me . oufMlM td*K,ore:> 50 I

I
I

IEOUCARE I J tiriLlofVP cheque postal urrter fpr £"
l^aStoanaStj^,,

swSxsav l A,Wress

Lai f» cM iww'il H'lr S«nd

*LL^a.'iECASir?rTf>'Off

'GRAPHICS
TOOLKIT

22mvctTtnp/*ACHtN€CQ&E
yfiut Sii'trAr-' it<Z n&irwr* tifttfirw *

IZ-K-B 1 ■ tCK BfcMOMLY.l

Di.-.nj n-irfW Ut-jwb C- UviflLm

yiHi" nyj||--,7tiai-HC».oni^»pfl w*iich
iq rirtipAjd in ■ HtM alJilirnam.
F«»gro**FHl Onldll 'ju lfui, i&
'pnubBCI i^niing-iTiancKjriiJfl
yaiar ici**n

Bod^iUnkwHHt* □^■*. i kiiW
loumj ihu kO^ia OF yi^ul- «*Mtrt
-n- F.3 hk : -.■ h^ ^«-J it

■Nljhir-Hll

RHHat»«ny nijmt«rol linfll jWU

Hwci'ir.illirl>n|] it 4viv h na vrxj

KWCl'lP . BT flXJT ChOHHI-

ctiinctei

Hftrtfii :,Dfivins ill ciMuciirt

M-thnir inirwia >Mloa ixwltgiM

iflRLL

fTlFH PAftlbUI dWile-MIl

UP DOWN,-. FFT FtlQNT Alhpi

r «,.n i-il PRlhtT poMiOA HI Ine

lints. Iiiiii iiiijrf.nlm!!

EiHpilrvl rro-59 na^l PttNl

posil or io iifsl odil linn
Scroll FiclhViht*
UPiCHOLL LXUftN^CHOl L.
HIQHT5CRQI,; iVFfTSCWtL
fciull f.>yyr ^i-gnrfi |Pq> tfinKliOn

Mtomd

OnpcrwnfOriicnvftfi I j'ni voui
Kiwnan uran

B«*-JnniJiiraOii.Clill'ill* <f<vf
ItI.i-hhip I;y y-:iur ^hili'ihi!

Art f SSf-N ^*l inyirAan r* -flijf

TOOLKIT

I Bill I 'HT tfi 1 hlvl FtMlHB]!^

r^r4h<i4fi| |n*J[L/A3avin F j l i«Iif'urtAi!
^irrfirj ■

LlrppirHimtMr pou siifif imniriQ

1UnlKMr<|] ircrCfiHIfll liiv$.
GOT&J inLTGQEAJB i ir^lLfdrpfl m
*ihh rtKiumlMf

B**4£h MHt Liil vBjr.tifJi. Ini- inrt.
■■il 1 ! hs^hiy Iii-fh U^nH|lnjBng
JCH&tii'nnl ij.rtiJiclB* 1

5**pn;h -md ntfHK* • tliirgdi

■5*«rp WIC Urincfl D>H ■ en ir»Ll*H It
YOUVTHfiMra.

fiHifuci ■ iftttii fLu howmny
'i«*bpiiii srfji. n*vH hfh

SOCIAL -GRAPHICS
ROUTINES

HnwrvipMiMi* ui»fl«h-tt
nnir Bf)#n on i Jab I &»tui»

1 ■■< I I pCiiM ICP4WI mmlAJ-vllj*

wilh pcaji ip->:!l«*ac'iaPU' i«i

[Hi -pDM" bLhkM^ Ii.-i4> nivfiH

iiOTa

TAPt ROUTINE pwidH.1

l.M-TIT VVAJT CDflClllUfl UWII Hi

wfifl*l i» nfE4iWd «n lf*« caibfclla
W |Kil

**' in»i» ramir-f-L it* .niin.ni m
"■■Ki'irif.';* «ro lirffjirMi tiki
upcFTily IKaryiXti ^k)i:inui^ RAM
IP IP-LJKditHir av. 'iiB'^in^rii ■ ■

pop 1-6K o^lv ci frfri'ja mv

^Battleships &

rCRUlStRSGAME

Fifll Li."Ti[iu1«r iHr*i;ir nl lhi|g
pOflutAi ojffiti <jf ^1rj|frj, *nri

ttpciiLi* Ekiifigixlion t-p*
i^vmn-K E^BbK-arhiheoa-ji-iiViul
•puv l '-pel I*ibp Idc«I# jytd (hnsi-nv
Iho-rarroutBr - ! 'tool Vi-suai
di^c-iHy rfwAAtii hiti *nd ir-t-fu**
rmictd !i^<: ( ; #*j njn og ■■■ 4

$*+rch -ttd PqijHiCI m-i| l4iic n
Ihestrflfln MrrTFiir, CCf.ui IHOCfj^l

Ch*char*Lliiv p gu iip«cily ■■ i • i ;<

rotate n #iin >uui ii*i.

crnii*ci*y,

Squkni iKdMi a i^Luin nr

i*:i-vium 'ium vimrHwriiieccc

i^irtlir^lrrt

An IRtH 'ouMnag irr vi JTmcNn

«m -nr SUKH-FASt mponii -

ujWPt H3 iijul-t jli:l- ,

a*. Dl yuur flAH utd irsi| iP-Ji>ofcF*
ipici lo om bn« mw (Mwr* i
roOLHTctair.r.b*3AiFy-j

TrMrt£iiAiMiaK*s,Hi|kf> * ii- :

uD|M>i]l I'W [irgyriiri.a cochahiqF
IftfrAjl "f-iMjrim p!US 1

Ouu*»rl wli^i cPiirrpUn

Al| pnen m luffp- rfiClUil'rt

10K RAM PACK

OiMJ K^SBfl^&Kj

QuHl ilnMriip IPm bail pi#il|ti
Ofui FP:FF Allan Arlfc-i
|TK IJI f iW# pi n j i Mrt"t

Viiiu.t&HrtuMt

F>j|ip Ciuii' iBHi'.fil iixl Db*<A^I*td

lyttdM- iiiUing nw »MPP+P llP-n

hYA:- 1»- j

ConpildblAi wwrn pn-il*<

nfcte -rcibb-r fKotalwiii

>-,«'*: i. AMa^Bpl ■■■i> -■ |g| |i-
D4rf*Cl LC--||J>LihvilTi ■,n i sr/lft1

ifflttl HMIKH '^i mk.'C4ai.K
nC-4QV (MaVii ittrta 4*>4b | ■

■ 64K RAM PACK.

B«'l'n ij^ighiy Iftir** >fM DVl
■jih-'n^rriiipiitApCTTftlFhQJY rd pCuji

2X4i.wnlfi iK|'*m|i dirTMniKDrtii

mj lirgsY Ipujp ItM IfrK **iirn Path

■>tny«q|

DVf«MS«firow« JAL£AMJ«ri ali PfMCES aW af-fmla-li* FrjPFXPijPr 'JHCuitXiG *i*waJl poat itur
■ ■^-ULMT-Ainv M A«Wih^€*LiN^ :•*>«£* 6*L>t n '.vauADUI p.i »^vn B*--S»-iOR fOtiAOwnu l LLHtour
bUOE PAtABlE ID jflS SOfnilil ItSA^ICM isOPIUJ-i , ' i [UtI ^ IT404* PttElPI '■«' ' i""Dt n

11 WATSIO* A'jFULilL HKWTXNM, HttHK AMIDJIJ t>l>p<nH> * IfHBtHrl

38

SINCLAIR USER August 1932

competition

Pretend to be
Ian Botham:
win a printer

This month we are awarding the last of our five Sinclair printers to our
monthly competition, for which we expect the response to be as good as tor

the first four.

To continue the emphasis of our Bumper Summer Special, we would like

vou to write a program to simulate the game of cricket. There is no umit to

the size of memory which can be used but we must insist that entries are on

cassette, accompanied by a typed or beauhfully hanoVwrinen hshng^

The judges will be looking for a program which attempts to include as many

of ^complexities of the game as possible. The Owzat form of the game

wiD not be sufficient.
As a tie-break, should one be necessary, we want you to write a slogan ((

beginning with the words: "I read Sinclair User because

Entries must reach us by August 16.
The usual rules about the editor's decision being final and employees ot

ECC Publications being ineligible apply.

\ ^Letlu^ ^*

\ sincl° irU

ie .breaV- 1 «■*

\
\

a tie-

■ ■

4 *

\
\
\

. *

■ ■

■ >

\
\

SINCLAIRUSEH August 1982

Sfl

ZX81

16K

TASWORD

WORD PROCESSING ON THE ZX81!

Your 2X81 becomes a word processor with TASWORD. Type «n
lauars, documents arid pictures, stare them on cape, arvd edn and
update existing documents. With a printer, which is not essential,
you can print your documents.
TASWORD FEATURES INCLUDE

• OVER 300 LINES of tuxl in a (Out file.

• CURSOR CONTHOL and auto repeat on all f<eys.

• SCROLL up and down through the text file

• AUTOMATIC word-wrap and right -justification.

• FULL ZX81 character set including inverse characters and
graphics symbols.

• INSERTION AND DELETION of lines and characters,

• A HELP PAGE onto the screen at ihe touch of a key.

• CENTRE l&xt 00 the scftiun. and 'nuvt.' !i>xl lt»fl and right.

• REFORMING ol edited teat to a neat layout with a single
keystroke.

TASWORD TUTOR

We send you s manual and a cassette One side contains
TASWQHD. The at her side contains TASWORD and TASWORD
TUTOR. This teaches you Word practissn'rg using TASWORD. Mo
programming knowledge is required to use TASWORD

Mail order only.

tb.tjU Mly inclusive

Allow up to 14 days delivery.

Please mafce cheques'?. 0. payable lo

TASMAN SOFTWARE

17 HARTLEY CRESCENT, LEEDS LS6 2LL

ZX Software

SCREEN KIT 1

MORE POWER TO YOUR SCREEN

in Basic progra ms ____
BORDERS ■ any siie - anywhere on screen f^ziiT* - '

SCROLL in ALL FOUR direction* l 4KioG4K ,

FILL SCREEN any graphic or character I ,,.;.*« ■

CLEAR and REVERSE PART OF SCREEN any pari * ~+

FLASHING CURSOR - anywhere on screen simulates INPUT

1* DATA FILES

SAVE MSK VARIABLES W WKlt

LOAD back into AN* jrojurn
ill *1 DOUBLE into

ind MtMOSV LEFT
mm byte ol machine ckI* |»p INSTAMTApHOUS iC« EN IESPOHSE

•Becomes pari r>1 jrnur Basic |naB,ram •tan De aaoed 1d Eni1in( jjrQfi im

£5 7Q incvAUP

ZXMC

SUPERB VALUE

c.w.o

MACHINE CODE DE BUG/MONITOR

At las: C OMPLETE FR E E DO H FRO M BASIC lor ntac h i ne code programmers

•Verwlile entry comrranns lor Hei

code and String ill by
•Cnmprehen^r^ Run 4 Se-nur rnrniiandu including

HEGlSTEftS DlSFLAr t BftEWOINli

•SAVE, LOAD, VERIFY AT DOUBLE S rt of RAM

zxTT

•Hej Sump In printer far Ami copy
• Loessenlial Lnnimr^ foi M£ pfOaTaflHTum
•Occupies J'tK RAH in Bass area
•Supplied cm cassfftf «irh 36 pate manual

•F asl machine code murines riper j-ne.

from Bass: area ol KAM
•wm« gnu M,C prwrjm.i aki« Bwic «h

Screen memory ID F ILEt never mnues
•StLf CONTAINED deign Id tfe «ri(ws
p«)|;rammei - Lanrnr be used with Basic programs

£7.50

IflC VAT i P t P
CiVO

REM-LOAD MACHINE CODE ENTRY/DE BUG

•A rerun* ur 2* MC wilhuul 11* S>VEAO*D,'Vtfl IF 1 facilities
•E N!E«. RUK, M BUG nachinr code in Basic RFhi linn
•Operates (rem above HftHfOP
•C jrCiHtibilily witri 9*s«;
•Suppliers en cassette with
JO page manual larONLT
SA£ far more detail Ol software

£6.95

Int VAT fc P + P

6 CORKSCREW HILL WEST HICKHAM. KENT BR4 968

Hail orrtcf wily - Mow II days deJorery
PLEASE STATt WMPUTEIl MOOfL

ZX81/16K SOFTWARE

"STARTREK" £4.95

16K STARTREK: Exciting space adventure game including
klingons starbases, phasors, 8 * 8 gala*y, 4- levels of play, long
and short range scanners, etc,

"SUPER WIMPUS" £4.95

IBK SUPER WUMPUS: Can you hunt and catch the
mysterious wumpus in his underground labyrinth? Intriguing
underground adventure.

"GRAPHIC-GOLF" £4,95

16K GRAPHIC GOLF: Try out your golfing expertise, on the
Computer's golf course, 18-different graphically display holes.
Hazards, include lakes, trees, wind, rough etc.

"GAMES PACK 1" £4.95

16K GAMES PACK 1 ; Famastic value tor money, nearly SOK of
programs on one cassette. Five games including "Real Time
Graphic" Lunar Lander, Starwars, Hammurabi, Minefield,
Mastermind,

ZX ARCADE ACTION
NEW!I"MUNCHERM" £5.95

Ai last Pscmsn for your ZX-81, all the arcade features plus!?
software for the Q5 character board,

"SPACE-INVADERS" £4.96

Simply the best yet, the closest thing to real invaders on the
ZX81. Pull arcade features I including T or 2 player option and
software to drive the QS character-board,

□ "ASTEROIDS" £5.95

Authentic representation of the arcade game including L. R.
thrust and fire controls. 5-leveEs of play and alian spaceships.

D

DROPOUT"

£5.95

Exciting NEW arcade game. Can you destroy the aliens before
they build up in their atomic plies and overwhelm you,
Dealers enquires welcome. generous discounts.

When ctrdenng 2 or mors dfdutf f 100 Send 5 A E. for Calais
Turk bo*e(s) required.
Cheques/ POs payable to "SILVERSOFT

Name

Addrm

W ANTE D ZXSl , Spectrum. BBC Micro Software

F ti'MliTil nnynltiris S A E Ir^r f4er*l&

All Arcade games run in 4K

SILVERSOFTfDep. SU7|
35 8adet Park, Bowerhill,
Melkshem, Wiltshire.

hilNULAIRUSEH AiijjtM IFWJ2

Sinclair user
club

Membership fee
can be recovered

Prices cut by Thurnall

FOLLOWING the good response to
our Sinclair User Club, we have
decided to make an extra special
series of offers to our growing
membership this month.

Two offers will be available ex-
clusively to club members, If advantage is
taken of both, they will cover the cost of
membership many times over.

We are able to allow members the
opportunity to buy a series of software
items and hardware add-ons at discount
prices.

Members will be able to obtain a 20
percent discount off all the I K Greye
range of software. J K Greye produces
some of the best software on the market.
Following its remarkable 3D Monster
Maze, recently it has introduced 3D
Defender, which our reviewer this month
considers to be another success.

Those and the rest of the J K Greye
range are now available at a discount of
20 percent.

The offer is available only through the
Sinclair User Club and cannot be offers you can
obtained in any of the retail outlets which membership

Our other offer features Thurnall Elec-
tronics, which produces a number of
hardware add-ons for the ZX-B1. Among
the products available from Thurnall are
input/output ports, motherboards and
joysticks.

All these Thurnall goods we can offer
to members at a discount of 10 percent.

The discounts from J K Greye and

Thurnall Electronics are open until the

end of August. To allow new members to

take advantage of these very generous

include an order with your

application. A form is

dock the J K Greye range.

printed below

f K Greye Software

List price

Club price

Gam est apt'

£3.95

£3.15

Game st ape 2

£3.95

£3-15

Catacombs

£4.95

£3.95

3D Monster Maze

£4.95

£3.95

3D Defender

£4.95

£3.95

Breakout

£1.95

£1.55

Thurnall Electronics

list price

Club price

Input/output port (kit)

£14.95

£13.45

assembled

£17.95

£16.55

Four-channel relay box

£14.95

£13.45

Eight* way transistor driver £9.85

£8.85

Eight- way indicator unit

£12.95

£11.65

Joystick

£12.95

£11.65

Motherboard

£15.95

£14,35

Power supply

£4.95

£4.45

Full details of all these items can be
found in advertisements in Sinclair User.

Facilities to

include

Spectrum

THE USER CLUB is to
expand its facilities to
cater for the growing
number of Spectrum
owners. For the same
annual subscription of £12
they will be able to lake
advantage of the extra
benefits which have been
available to other ZX
owners for the last two
months.

The benefits include the
bi-monthly, cassette-
based newsletter which is
being re-recorded so that
it can be used with the
Spectrum and will contain
Spectrum programs.

To ensure that each
member receives the
correct cassette, please
denote which machine you
own by ticking the box on
the application form below.

Meet the first
member of our
club on p.62

MEMBERSHIP ~"
FORM

I wish to join the Sinclair User Club and enclose
my subscription of £12

Name

Address

Which computer do you own?

ZX-81 □ Spectrum D

Send your coupons to Sinclair User Club.
ECC Publications, 30-31 Islington Green, London
Nl 8BJ. Cheques should be made payable to
Sinclair User Club.

SINCLAIR USER A ug us 1 1 982

t,i

THE FIRST member of
our Sinclair User
Club is an enthusiastic
Sinclair supporter. He
was one of the first to ob-
tain a ZX-til, he Look a
years subscription for
Sinclair Usbt as soon as it
was announced and he
placed his order for the
Spectrum some lime ago,

** When Sinclair brought
out the ZX-BO I decided to
wait, but when the ZX-fll
arrived I put in an order
straight away. "Peter
Lown, 62 , of Strathmore
Avenue, Hull, North
Humberside, said. He
bought it with the 16K
RAM pack and the printer.
A telecommunications

Sinclair helps in m
work, rest and play •

manager with a large in-
ternational company,
Lown has made full use of
his system both for work
and in his hobby of motor
sport.

"I use it to run telephone
traffic analysis. It is not
complicated, just number-
crunching, but there is a
good deal of work involved
and it saves me plenty of
time", he said.

Recently he has devel-
oped a program to display
tic; tails and results of
motor rallies. A friend has
built him a regulator for
converting 12V supply to

the 9V needed for the
Sinclair to be used away
from a mains supply.

It had its first showing
towards the end of June in
the Cossack Rally in North
Humberside. At the start it
listed details of the com-
petitors, scrolling them up
so that all of them could be
included. At the end it pro-
vided the results.

"It took about 25
minutes to input all the
figures but we were able to
do it as the cars arrived so
the results were ready
within two minutes of the
last competitor finishing,

which was the t ime needed
to sort through all the in-
formation," Lown said.

He first had contact
with computers 25 years
ago and was a founder
member of the Hull and
District branch of the
British Computer Society.
In those day s he w as work-
ing on a National Elliott
machine which, though
having the same capacity
as the ZX-B1. was the size
of ""a side of a house".

Britain

Club: Ken Knight. 22 Mount Street
. Meetings: first Wednesday and third

J. Palmer (031 661 3183) or K Milrhell
second Wednesday of the month at

Aylesbury ZX Computer

Aylesbury [51H1 ur 630B67

Thursday of the month

Edinburgh ZX Users' Club

{031 334 S4B3). Meetings

Cla reman t Hotel.

EZl G-Edututjund.1 ZX-60'Bl Users' Group: Eric Deeson, Hlghgate

School. Birmingham B12 9DS-

Giasgow ZX-BO/81 Users' Club: Jan Watt, 107 Greenwood Road,

Clarkslon, Glasgow G76 7LW (041 638. 1241). Meetings; second and

fourth monday of each mnnlh.

Hassocks ZX Micro User Club, Susses: Paul King (Hassocks 4530).

inverchde ZX-B1 Users" Club: Robert Watt, 9 St, John's Road.

Gourock. Renfrewshire. PA 19 lPL [Gourock 39967}. Meetings:

Every other week on Monday at Greenock Society of the Deaf. Kelly

Street, Greenock.

Keighley Computer Club: Colin Price, Redholl, Ingrnw. Keighlny

(603133).

National ZX-BO and ZXBt Users' Club: 44-46 Earls Court Rami

London Wfl 6EJ.

North Hertfordshire Home Computer Club: R Crutchfioiri. 2

Durham Road.. Stevenage; Meetings: first Friday of the month at the

Settlemoni, NbysUs Road, Letchworth.

North London Hobby Computer Club: ZX users' group meets at

North London Polytechnic, Holloway Road, London N7 each

Monday, 6pm.

Nottingham Microcomputer Club: ZX-dOVBI users' group, G E

Rasford, 9 Holme Close, The Pastures. Wooduorough, Nottingham.

Orpington Computer Club: Ruger Pyalt, 23 Arunrlnl Drive,

Orpington, Kent, (Orpington 20281).

Perth and District Amateur Computer Society: Alaslair

MacPherson, 154 Oak bank Road, Perth Pill ll'lA (29633)

Meetings: third Tuesday of each month at Hunters Lodge Motel.

Bank foot,

Post Office Users' Club: Vernon Quainlain, Head Pnsl Office, St

Martin's In Grand. London. ECl,

Scunthorpe ZX Club: C P Ha ie I ton. 26 Riles lone Place, Boltesfurd

Scunthorpe; [0724 63466]

Sheffield: Andrew Moore, 1 Ketton Avenue. Sheffield SB BPA

would like people interested in starling a club in the area to contact

him enclosing a atamped-addreaaed envelope for oVtaiis

Worle Computer Club: S W Rnbone, IB Castle Road, Worle,

Weston-super-Mare BS22 9JW (Weston-super-Mare 513066],

Meetings: Woudsprtngs Inn, Worle. on alternate Mondays,

ZX Guaranteed; G A Banker. 29Chadderton Drive, Unswurth. Bury.

Lancashire, Exchanges information and programs throughout the

country.

ZX-H0/ZX81 Users' Club: PO Box 159. KLngstun-cin-Thames. A
postal club.

Overseas

Belgium, France. Luxembourg: Club Sinclair, Raymond Balz. 36

Chomin dn Moulin 3B, B-1328 Chain, Belgium (322 6537466}

Belgium, Netherlands: Microcomputer Vereniging BZW. Paul

Clenisson, Prigs I er de rEpeestraal 14, B-1200 Brussels. Belgium

(322 7349954]

Denmark: Danrnarfcfl National ZX-80J61 Klub (DNZK], Jens Larson.

Skovmoscvoj 6.4200 Slag&lese, post giro 1 46 24 66.

East Netherlands; Jonathan Mayer, VanSpaen Slraat 22,6524 H,N.

Ni|megen: ((180 223411).

Germany; ZX-SO Club, a postal dub; contact Thomas JanCKyk,

Hameln, Postfat-h 65 D-3250 HameJn, Germany.

Indonesia: lakarla ZX-B0V81 Users' Club. 73 Cnnc Crionain. Baile

Atha,Clialh I.

Republic of Ireland: Irish ZX-80'Bl Users Club, 73 Cnot Crionain.

Bade Atha, Cliath 1.

Spain: Ciuh National do Usuries del ZX-fll, Joseph-Qriol TomnH,

Avda. de Madrid, No 203 207. 10, 3h nw:, A Bflreelone-14 Espana.

United States: Bay Area ZX-BO User Group. 2660 Las Aromas.

O silt I and CA94611. — Harvard Group. Bolton Road, Harvard MA

01451; (617 456 3967),

82

SINCLAIR USER August I9&2

special
offer

Build your own

Sinclair

Special ZX-81 Kit Offer

ONLY £29-95 (plus p&p)

SAVE £20 on a Sinclair ZX-81 kit, A special

offer open only to readers of Sinclair User

has been negotiated with Sinclair Research,

which means you can buy the world-beating

ZX-81 for just £29.95 (plus post and packing).

Stocks are limited, so be sure to place your

order soon. Allow 28 days for delivery.

Maximum four units per applicant.

To; Sinclair User Special Offer,

ECC Publications, 30-31 Islington Green, London, Nl 8BJ

Please send me„ ZX-81 kit(s) at the special Sinclair User price of

£29.95 plus £2.95 p&p.

Please tick if you require a VAT receipt □

*] enclose a cheque/postal order payable to Sinclair Research Ltd for £_

*Please charge to my Access/BarciaycaraVTmstcard account no

* Please delete/complete aa applicable

Signature -

l_

Name Mr/Mrs/Miss
Address .

J

SINCLAIRUSER AuflusMW

63

ZKfll BDFTUJflHE

NIGHT GUNNER

Enemy aircraft approaching from the rear ! '
Can you defend your plane against enemy attach ?
Beware, the more you shoot down, the faster they get.

An exciting machine code video game with impressive
graphics. Features include: best score of the day, auto-
repeat on the control keys, auto-return to the self
demonstrating title page-
Requires 16k RAM. Supplied on tape, with instructions,

Action packed fun for only £3-45

FIGHTER PILOT

15 feet — 7 feet Touchdown \

Another successful instrument landing Appoaching
at 150 knots is not always as easy as thjs.You are in
full control from take-off to landing during this
real-time flight simulation of a jet fighter. The sky
is the limit! Fly a different mission every time. Endless
scope for improving your instrument flying skills
16k RAM Required, Suppled on tape, with full instructions.

Supervalue at £3 45

All prices inclusive (Overseas add CO 5 Sp&p per tape '
All products guaranteed, refund if not satisified

Digital Integration.

22 t Ash Church Road,
Ash t Alder shot.
Hants, GU12 6LX.

MAIL ORDER ONLY

Ultra-Tech Services offer for

mathematicians & students the

following programs on cassettes, for

The16K ZX-81,

1. Complex Numbers

This program provides 79 operations and functions to
apply to complex numbers.

2. Non-Linear Equations

Solution algorithms for both real and complex roots of
equations.

3. Numerical Analysis

Integration, regression and Monte-Carlo methods for
the ZX-81.

Each cassette costs C6. 95 (inc. VAT) or all 3 may be
purchased for £78.00. Cheques or postal orders made
payable to M. V.R.H. Ltd. should be sent to:

Urtra-Tech Services
30A, Billing Road

Northampton.

RSOFT

7 MAESAFALLEN, BOW ST, DYFED, SY24 5BA

ZX81 & Spectrum
Games

Now NEW LOW prices!!!!

PROGRAM OLD

Chess 1.4 1000

10 levels mc

NEW 81 SPECTRUM
8.95

Adventure 10 00 8 95

140 locations cased on the original
[At C10 00 wei! worth the money
Sinclair User Issue 2 review)

9 95"

Invaders 5.00

Fast m c arcade action

J 45

Mazeman 5 00 4 45

All the features of the original
arcade version m c

'requires 48k Spectrum

All prices are inclusive
Return of post service

4.95

ZX81, SPECTRUM OWNERS

ITS HERE! THE BOOM VOU VE BEEN WAITING FORI

LEARN WITH YOUR SINCLAIR MICRO COMFUTIR

BY FRANK ORVILLE

. V .

I'NIH.MM ■

MHAbETtCftL UBHp
Mis* as . Th>» CompuUT

if*™ .

Input Up to 450

intti than,

A v»ri apjiayafeia

mi iK TCAffi Hurt It Out jiIJ th* lnfim-
EtT«i yOU mMd to know about
■tOrtflacj* lMnt for hauaar pureh4i»a; r

* m\« iiy. tut* Li*», ttcm*. h*ho

J. i

fiint nut m calendar

Hirtrting in Any ^iuf ,

LI TTtK NKJTlHt;

Htoii ujf to ZQ
■Ki> Mr its |rtt>ra

»na cuk^i mt: tn i«; am j«uitg

ping program wTiIf'Ti laaaabrn up tu
200 vcidtt frun your text and mry
tinr pu type- in 4 nam IrLtajr, tt
Jttl'aptu to A.Lk?ati 1L the word you
4re Currently typinq. If thai ujuofta,
printed trlou thit I irai , 1* ClUItn,
Ih" CtaiE!l«ta> tfuid II plaCvd M it]i a
roll owing UpdC* in oner iLrclu.

U CEOCHAJWlf UU1Z DrAV. i -p of (J*

Hr 11 lnri lvlen and Horki, thtouflh 4 }5
iiiund (rufE J" which fiHJ ImV* Id pick
nit 1 h- run* Of the flashing

1 uCf t njin . Vtr ry cdini t 1 una 1 4

ALSll if yuu haw a Full-aixatd

Kf y bod-i d b you can 1.1*4 r h your aah L f t

type.

■lTifitani not liujubl* for ^pahctruai.

Hwrn Kith Y"iHj£ SJnrHair H lcro-tumput«r £S InLliuivr
lioofc with *H»t nf c*.fiaetteB. f-tl.SO JnL-Iunivr

S#nd P.O. Of rtliBrjed i - h,iijij*. pude pay4t»|4 to hlr.J-'jE

Mr .P,L,Dunov4n»

i mxon nt tv«,

StOIMyDAtaTf

jJjLTVltl^L_j_l J Ufa

.uunav^n, to 1 ■

64

SINCLAIR USER August 1W2

ZUCKMAN

The first authentic ZX8J
(IS/Oversion of 'PUCKMAN'

* ALL Machine Code /usw h*o
+ FOUR independent Ghosts

* Trail, £nergy f>os ts etc,

* High-score 'Half of Fame

* Authentic Arcade Action

only £5-95 inc. P&Pfrom:

DJL SOFTWARE.

9 Tweed CIdm. Swindon, Witts.

"

MUSIC LEARNING AIDS - a
range of programs for 16K ZX8t to
help young people learning to read
music Sae, please, for free
catalogue. Brian Magus, 19
WeStfield Drive, Loughborough.
Laics LE 11 3QJ.

For ZXB1 with 1BK RAM. Three
programs on one cassette. Flight
Demonstration, Flight Simulation
and Flight Test. These are semi

serious programs using an aircraft
digital instrument panel. £5
cassette and instructions. Sqn Ldr
Peter Evans, 5 Broad meadow,
Bolton BL7 9AY.

EDUCATION

Compu1»r» For EdMcaibon prmffl their
•Learn Abnui It' Serisslw the Z*S1 11 6M
This series has b»en wmMon t*v eeac hpr* and
.', m true aAjoitinnal tool. The programs jre
sjinblafar use v«th children »B*d 7-1 2 yeara.
Each program m rrnnu driven- and makasfull
uae ot gi»ph»e*-

Psronis and Mdtane- thaw programs wstr
will g»v« ytm< children an unfair ndvflfiiigel

Up*

No. Sute A Sttfr B

l Telling Tima 12/24 hr clock

2. FtsatfirvH «rapn» Staph pinning

3. Learning IractoFts U*r>g fraclioni
Mk Volume.' capacity Arna.'pflrwwtuf

5. Menial anthnteiic SpviiiAS

H.OOfKT i:dut>ne (2 programs! or (18 for lh<f
ccwnplele series

COMPUTERS FOR EDUCATION
58 Dovecote Lana, Spring h*id, Okiham

ZX-81 KITS

Cure Top Line Slant and Ram
Pack Wobble £2.95. Inverse
Video Module £2 95. Built
£3.65, Repeat Key £3.75. Bu<lt
£4 96 All Kits en-stock. Please
add40pP'P.

Mr B. A- Readar,

45 Alfred St. Kings Heath,

Birmingham B14 7HG

ZX PRINTING SERVICE
FOR YOUR ZX80 IBK ROM).
ZX81 programs. Only 1 pence for 3
lines of 32 characters, plus 20 pence

p+p. (minimum 50 pence please I,
Send cheque/ PC to: T.F, Payne,
194 Stockwood Lane, Stockwocd,
Bristol BS14 8NG, enclosing your
program casselte and details of
program name(s) and your name
and address.

16 ZXB1 HAM RADIO program
Data handling program for Ham
Radios- Listings available at £4.00
each. Send sae. for details or
orders for Ham Radio to B-L.
CotgrovB, 46 Arcadian Gardens.
Hadleigh, Benfleet. Essex.

ZX91 with 16K hardly ever used
like brand new, still in box, together
with books and software worth
E38 Bargain at £110 worth fl45.
Write to Tariq Mir, 5 Beatrice Rd,
Southall, Middlesex or phone IFri-
Sun, midday-midnight onlyl
571-0777-

LET YOUR ZX31 help you vuin
money on horse races. This fabu
lout IK programme picked 8
winners from 8 races on the very

first day it was ever tested
120.3.321. Send a cheque or P.O.
for E10.00.for the cassette and full
operating instructions to the
Butronics Co-, 45 B romp ton Road,
London S W3- 4 Mail order only please)

ZX81 MULTISEQUENCER

Using unmodified ZXBM4K laparl
from amp> this program provides you
with an instrument covering over &
ottaws with full editing facilniBS to
write 37 independent sequ&nces of up
to 16 notes, which c*n be played in any
order under redlume control- tunw are
iiored when program saved- Fasi
lempo gives synthesiser effects. Mustc
type notation throughout .
Sand E5 for ca»S*tte and instruc-
tions to: V. Waynes. 10 Ashleke Rd,
Streatham. London SW1S

ZX 81 TEMPERATURE
SENSORS
Uses earpiece socket, with
application program listing and
waterproof probe. Including UK
p&p £17.50. Free leaflet
Cheshire Micro Design, S6
Close Lane, Alsager, Stoke on
Trent

r

so v t RAX -i>.

[1RHW POKER

9W1 wil fi .1 h icrl it »[ i 1 <il"< If'i IIhH ' * ii'iiH I

rttilHofuirr otiose wwnhlmfl taaddfcttw

IwnH' iMM^i on irjIlit'PikJnrjl jmirklljil HI
aild |iMiLuhii|t r«0«n.lMhJr HT^'h" ft
(In ra.iM.|l(. only ri.M

BINfKI

lm>'l bp uiucii.il il<-' Slur, vonr J\Hl *\W,

fjniilt jml frteiuli in * |i|r.i J -.i"i k •' lh1

InllRn IIh- itWIipkll*' |irmliiM-i ■ irjti>

ill krlh Hi vim H^ril Jinl iJi^.U^-. Mil "

Ixjjnt *"M tbjM irrimLrT irquiicd)
Hnv < jwllc ffllh l"S

Hruli iHCKMirft cm mir ra n iWl |inl»- Ib.vy

Ml yrien ««■ p*p

rhngwii Mt P.Ol* In
SlJPTFiA* (Pep SUf.
lb. riiinl Avenur.
Bantu

Avr.m

Mail intir.t "iilH

2X81 SOFTWARE

Stockexchange

Try your hand at making a

fortune on the stockmarket,

Very realistic game Supplied

on cassette 16K £5 .95.

Rubic Solver

Program to solve the Rub<c

cube supplied on cassettes -

16KC2.95.

All Prices inclusive

Programs fully guaranteed

SR Software

61 St Stephens Avenue

London W12 8JE. Mail order

only.

PEP

THE PROGRAM ENHANCEMENT
PACKAGE FOR THE ZXB1 [18KI
A SU itef o' ed&y to "se machine coda
rounnfiide^igri-ert tO Ironaform your
Basw: (jTOgiamE.
DEFINED SCROLL REGION
1 line to whole screen SCROLL up
or down. FILL SCREEN any
Mb -m CHANGE BACKGROUND
CHANGE FOREGROUND
INVERSE VIDEO FLASH SCREEN
CLEAR SCREEN wnlraul chan^ifl
print position.
Supplied cm iaue with a6K DEMO
PROGRAM and a FULL insir.i
booklet
ONLYEB.Mmclpifp

IBK GAMES PROGRAMS

GOLF 1 or 2 Payers Fantasiic

graphics

MINEFIELD Slew ywir timk to Sfltely.

Very addkMiv"
INVADERS Wnh snoftky SMART

BOMBS

MANHUNT Evade the R*«k* if you can

FANTASTIC VALUE AT ONLY £3 7$

each inel. pfcrp

Send iq R & R SOFTWARE

34 Bourton Road,

GLOUCESTER GL4 OLE

TRADE ENQUIRIES WELCOME

MACHINE CODE

GAMES
For the 16K-ZX81

RYU MAN the ZX i«mtin o( ilw

liopuLpr Putltman Artade Game.

S'PACi-FlGHTER Fly rn» bai*

againir the limiihsa fcKtw vl rhe surmv

BRIDGE BOMSEP. •- Do as much

rinmaoe as yuu can *«th a Nmiied

pn yto i d,

All for only f? 36

From MINDSEYE

12 North Orave Orivn.

L*«d* LS8 2NJ.

lTBST score- -latest scoee —la

ZXS1 16K RAM. Sinclair

learning lab and 2nd hand tape
recorder, also magazines and
labyrinth game, a bargain at £85
Phone Ingrehourne 76446.

USTER-AUSSIIBUSTEH-'AOSSIEB

POOLS FORECASTING PROGRAMME

EsfMClaliy deaijjneo lor Auirrahan r^u,uiii
Slar Value — Bnlii prsgramme* win

ZXB1-C9.00 MISOK-EieDO ■

POOLSOFT^

Tet. ( 0323 > aaoeo*

65

SINCLMRUSliR Attgnstl§83

MICRO WARES

MAKE MONEY, unique

program shows how. "At

Last' ,£3.95.

SAIL A YACHT, against wind,

tides:, hazards, adjust sails etc.

'Sailing", £395-

For Spactrum, ZXflV 16K

On quality checked tapes.

20Winstree, Basildon,

Essex. SSI 3 1 PG

ZXB1 + 16 K RAM C65 ono.
Sinclair built- D.-Wright r 3 Burford
Ave. MCR M31 1SH. Tel 061-746
2175

2X81 + 1GKHAM Sinclair built, in
original packing. All leads and
manual- Some books and
cassettes, can deliver. ESS one.
S, Mannon, 37 Clove rdale. Stoke
Prior, Brornsgrove, Wares. Tal.
Brornsgrove 70779.

SINCLAIH BUILT 2X91 6 1SK

ram pack. Plus leads, manual and
power pack. AH still boxed. Also
10K 3D maze program. Everything,
a bargain at £95. Nicholas Barker,
Highfield, Dairy Lane, Walberton,
Arundel, Sussex BN1S OPT. Tel.
YAPTON 551315.

-zxn ih* iDhwiF* -

COSMOS - Uvt your ti««[; Irom ths
ITiaFAudir>g jjieris in tfiii niiw m .' e space oame
unltidramilicflrlpiiics On YOU' ship's 5flfl3*T
scrwn. Efi.98

TABLc TUTOH - eemfrfaia rtianif driven
eouraa in fliulriphtari-nn iob'e» with
examples, last*, homework and answer
s*mt*FflTthBun4»ff lffi. C3 99

QUAHTET — a COfnjMndiLjm nl cro^vmiQrrl*,

puiitea and memory gem* imuWpli vh^ with
un ru 1 D JiMk ulmw f 3 99

TRIAD lhrno nnw pmijlns to tierplejl and

rrusrraifloufln Cubists £3.99
SufjofrM an cJ>*wit*. tie for catalogue,
Von^ii S oftM fe, 2S Crawford Road,
Hutfigld. Hertfordshire ALIO OPG

ZX81 16K "G3ZHY MORSE
CODE TUTOR'' Teach yourself
Morse Code with this comprehen-
sive self-tutor, Selectable options
to include tetters, numerals, punc-
tuation, user text; 5-30 wpm,
variable groups, random/ serial se-
quence, video check-back, uses
cassette o/p socket. Available on
TDK AD-C46 cassette with lull in
struclions £5.00. M.H. Irving G3Z,
22 Wheatley Way, Chalfont St
Peter, Bucks SL90JE.

SINCLAIR ZX91 with 16K Ram
Pack, manual, leads and adapter.
Also includes a unique anti-glitch
capacitor, 8 cassettes of software,
books and magazines. Offers in the
region of £100. For further details;
Tel; Thatcham (06351 644038.

If you have problems trying to make
a program sand ail the details of
what you want in it and I will try and
do it for only C2.50 for IK games
and £3- 00 for 16K games . M you want
any programmes copying please send
the listing to me and I will send the
program back for only £1.50 for IK
games and £2,50 for 16K games. If
any of you have a 4K graphics rom I
will make any games you want for
only £3.00. All the prog rammes are
changed each month.
Paul Waite, 3 Cornwall Ave,
MansfFeld, Notts NG1S 3JG-

UNIOUE 2X81 games and
pastimes requiring skills of concen-
tration and reaction. Please send
SAE for free list, G. Carr, 'Sero-
Sed-Serio', Tunbeck Ret, Wort-
well, Norfolk SP20 OH P.

16K ZX91 + DK graphics board +
Kayde keyboard leased) + BiPac
Sound Box. Many software cas-
settes, including Asteroids. Space
Invaders, chess and centipede + 1
book. All for £125 o.n.o. Ring
Lymington 10590) 76319,

16 K 2X-B1 with manual, leads,
etc, five of the best 16K games

around on original cassettes, in-
clude Chess, 3-D Monster Maze,
Star Trail etc, plus book on
machine code (worm £7). Only
C1 10, If you don't believe this is a
bargain, just ring 061-339 944fi for
more details, or write to 49 Crowbill
Rd, Ashton-under-Lyme, Lanes
OL79MB.

ZX81 - 16K

FOOTBALL POOLS PftOGRAM

* ban out, <n enter ctf pre*er«rK*, the tS mo*

RwV icor* rirmr: vfajci lha 16 rnOH ftary
rtfjfnet, dreiiva and away4
' Picks out the mufti on lha boo»m**n'
Head Ddda coupe™ tfiat hav* b*w ghiwi ow*
aanafbd oa*. CataJatas your ejgpectad proftti
' Ataw* the user to- update rh* abtjc "«ak by
wpak #* TPJlt* CWTW in

For a taiseiT* nf she oyoprarn, jjruj a* wornc
oofi h&tbt gtvmg * tumf u^nihw nf t/m-

HARTLANO SOFTWARE

(&*pi Si
8 PENZANCE PLACE, LONDON Wl 1 4PA

ZX 81 16K ADVENTURE GAME.

Full 16K used. Plenty of Action -
map supplied, plus detective game
of Logic (2-21 player?). Both on
cassette only £3.50. S. Taylor. 2
Greenway, Eitham, London SE9
5SZ,

ZX 81 plus 16K RAM. Thirteen
programs on cassettes. Manual,
book and mains adaptor. Mint
cond. £85. K Macdonald. 13
Cookson Rd, Sheffield, Yorks
(0742! 349943 anytime.

SCHOOL CHILDREN! I have
developed a program to enter and
RUN standard CESIL programs on
a 4K (or more) ZXB1: Cassette for
£4.95 from Timothy Skinner at, 1,
Summer Drive, Hoveton, Norfolk
NA12 80Y,

2X81 with 16K. Instruction books
and ICL programming course and
tapes, including all leads, and two

games £80 ono. S, Leigh, 47
Middle Lane. Epsom, Surrey. Tel,
Epsom 2B21S

Sell your used computer or peripherals through Sinclair
Supermart at low cost ... up to 30 words for only £5.

Nave you updated vo'Jr computer or od you n.D longer use thai add-on 7 Instead of
eavmg it lying around, turn it intocash be piBcmQ a classified advorTlsemfrni in
Sinclair Superman ant! reach etowrid 4 0.000 u*9»S ot Ihc Sinclair ZX syslBms.
Pleas-B write your advert isem^rit in the boxes below, one word per box. Underline
words r equ ired in bold type. Your name, address, a ncl /or telephone number
should: to included Pleest punt m frtoc* cipti&s

Mol» — (hit torvito iS open o^ly To private advertisers The advertisement will
appear in Erne aarl lesl possible issue

Name:

Address

Tel.
Have you included the tee of CS T

LaaaaHaaBHaVHI

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AD INDEX

Kempatuu

41

Melbourne House

4

Addictive Games

38

Moviadrotne Video

54

P, AltwaBser

17

MifTuwenj

54

Afdec Electronics

17

M.C. AsjiodptBu

44

Aberaoft

64

Microfuir

26

Artie CumpulniR

42

Memotech

21

Buf f e r Mic ru- Shop

26

Newn bb Technical Books

54

CrjrrjpuIeK Cosee

9

OesisSuflwHru

42

Ch mhrirlffi? ComputBr Shop

58

M.Orwin

2

D.K.Troiilea

67

Occam Software

12

DataAssette

IS

Pjrturenque

eo

Digital Integration

64

FhoentE

22

PI,. Donovan

64

Fas

20

Edurars

56

Mr Readman

57

D. Frita-h

17

Read-Out

48

Fuller Micro

tt

Sinclair 1 1

.52-53

tiewBOEL ConeuJ tan Is

57

Silicon Tricks

54

Haven Hardware

46

SlJvLTfiuFt

64

Hilderbay

42

SupartCLBrt

65-66

Interface

40

Serious Soli wars

46

fPS

22

Software Farm

32

1.K Greye

It

Tasman

80

THS

SB

Timedata

26

J.G. Prises

12

Ultra-Tech

u4

Kayde

66

Wiirkfortrff

57

M

SINCLAIR USER August 1982

'

MICHAEL ORWIN'S ZX81 CASSETTES

THE BEST SOFTWARE (BY VARIOUS AUTHORS) AT LOW PRICES

QUOTES i

' 'Michael Orwin's £5 Cassette Two is very good value.
It contains 10 stolid well designed games which work, offer
plenty of variety and choice, and are fun."

From the ZX Software review in

Your Computer, May '82 issue.

"I had your Invaders/ React cassette ... I was
delighted with this first cassette. "

P. Rubython, London NW10

"I have been intending to write to you for some days
to say how much I enjoy the games on 'Cassette One'
which you supplied me with earlier this month."

EM., London SW4

". . , i previously bought your Cassette One and
consider it to be good value for money!"

Richard Ross-Langley
Managing Director
Mine Of Information Ltd.

CASSETTE 2

Ten games in Basic for 16k ZX61

Cassette Two contains. Reversi, Awari, Laser Bases, Word
Mastermind, Rectangles, Crash, Roulette, Pontoon,
Penny Shoot and Gun Command.
Cassette Two costs £5.

CASSETTE 1

(eleven Ik programs)

machine code:

React, Invaders, Phantom aliens, Maze of death, Planet

lander, Bouncing letters, Bug splat.

Basic:

I Ching, Mastermind, Robots, Basic Hangman. PLUS

Large screen versions of Invaders and Maze of Death,

Ready for when you get 16k.

Cassette One costs £3.80

CASSETTE 3

8 programs for 16k ZX81

STARSHIP TROJAN

Repair your Starship before
disaster strikes. Hazards include
asphyxiation, radiation, escaped
biological specimens and plunging
into a Supernova.

STARTREK This version of the well known space

adventure game features variable Klingon mobility, and

graphic photon torpedo tracking.

PRINCESS OF KRAAL An adventure game.

BATTLE Strategy game for 1 to 4 players.

K A LAB Rl ASZ World's silliest card game, full of pointless

complicated rules.

CUBE Rubik Cube simulator, with lots of functions

including Backstep'.

SECRET MESSAGES This message coding program is

very txlp qexi jf .

MARTIAN CRICKET A simple but addictive game

(totally unlike Earth cricket) in machine code. The speed is

variable, and its top speed is very fast.

Cassette 3 costs £5.

CASSETTE 4

8 games for 16k ZX81

ZX-SCR AM BLE ( machine code* with 3 stages .

Bomb and shoot your way through the fortified caves.

GUNFIGHT
{machine code}

INVADERS
(machine code)

-'HOMi^e CEPDL'." SPORES. ™U
■ONIML B CLVCft SNB Y-OUH MISaXQf
iff TO CCITROY THE FUNJhUOIM E*
icppiHi BNTI-FUNGUS E-QHB^ ON

'■HEM .

GALAXY INVADERS (machine code)

Fleets of swooping and diving alien craft to fight off.

SNAKEBITE {machine code)

Eat the snake before it eats you. Variable speed.

(very fast at top speed),

LIFE {machine code)

A ZX81 version of the well known game.

3D TIC-TAC-TOE (Basic)

Played on a 4 * 4 x 4 board, this is a game for the
brain, it is very hard to beat the computer at rt.

7 of the 8 games are in machine code, because this is much faster than Basic. (Some
of these games were previously available from J. Steadman), Cassette 4 costs £5.

Recorded on quality cassettes, sent by first class post, from;
Michael Orwin, 26 Brownlow Rd. r Willesden, London NW10 9QL (mail order only please!

KA YDE Electronic Systems

/ \ 2X80/1

ZX KEYBOARD WITH
/ /\ I REPEAT KEY

Fully cased keyboard £37,95

Uncased keyboard,,.,.. £27.95

Keyboard Case ,„„.„ £10.95

Thrs is e highly professional keyboard using executr ia am fi-und on top quality

computers. It has a repeat key and comes complete in ilsown luxury case. This is a genuine

professional keyboard and should nor be confused with toy keyboards currently available on
me market.

KAYDE 16K RAM PACKS

The 16K RAMPACK simply plugs straight into iha user port at the rear of yogr computer It is fully com-
patible wrtn all accsssonesand needs no extra power and therefore it will run quite happily On your Sinclair
power supply ltdoes not over-heat and will not lose memory atall. As you may know some makes qor
" after being on for a w\

ES {£ XSSL I! CompS m^oac? %£££?"* *" " ^ *" ™ rt m ™' '"»■"» «S*

KAYDE FLEXIBLE RIBBON CONNECTOR >^M,

Stops movement of RAM PACK and other accessories ^T^To %

(Not needed with a KAYDE RAMPACK)

KAYDE AK GRAPHICS BOARD

The KAYDE Graphics Board is probably our best accessory yet. Ii fits neatly inside vat" ZX81 ll comes
complete with a pre-programmed 4K Graphics ROM. This wfll give nearly 450 extra graphics and with there
inverse makes a total of over nine hundred .

The KAYDE Graphics Board has laci!it«s for either 2K or RAM (for user definable graphics! 4K of ROM or
our 4K Tool Kit Chips that will be available shortfy. All the graphics are completely software controlled
therefore they can be written into your programmes. Here are a few examples A full set of sauce
invaders - Puckman - Bulks. Bomba - Tank* - Laser Bases and Alien Ships.

NO EXTRA POWER NEEDED

KAYDE 16K GRAPHICS BOARD SOFTWARE

Peckman: The oniv on of the popular arcade game.

Centipede: "In all I think this is the best presented moving graphic program I've yet seen" Phil Garrett

Interface.

Space Invaders: The best version available anywhere.
Graphic Software can only be used with a Graphics board

KA YDE 16K 81 SOFTWARE

^rface* 8 ' n a " ' ,h,nk ,hS ' 5 tKe bBSt presented movir| S graphics program I've yet seen" Phil Garratl

2 D 3 4 d^bit Maze that has corridors which may go left riaht uo down

Peckmen [the latest addition in 81 games I.

WW Y WAfT TO PA V MORE
FAST IMMEDIA TE DEL IV EH Y

Post to;

Dept SU

Kayde Electronic Systems Ltd

The Conge

Great Yarmouth

Norfolk NR30 7PJ

Tel: 0493 57367 (Dept SW

Don't Forget you can a/ways orde
on the telephone with your credit card

Ml products include VA T all hardware
comes fully built and tested with
a 14 day money back option

DEPT,

SU5

I enclose £
Name .

Address .

Please add £i. 50 P/Pfor all hardware and 5Qd for all software.
Please make cheques payable to Kayde Electronic Systems t fat